JP6843043B2 - Terminal equipment, base station equipment, and communication methods - Google Patents

Description

Embodiments of the present invention relate to techniques for terminal devices, base station devices, and communication methods that realize efficient communication.

In the standardization project 3GPP (3rd Generation Partnership Project), high-speed communication was realized by adopting an OFDM (Orthogonal Frequency-Division Multiplexing) communication method and flexible scheduling in a predetermined frequency and time unit called a resource block. Universal Terrestrial Radio Access (hereinafter referred to as E-UTRA) has been standardized.

In addition, 3GPP is studying Advanced E-UTRA, which realizes higher-speed data transmission and has upward compatibility with E-UTRA. In E-UTRA, the communication system was based on the premise of a network in which base station devices have almost the same cell configuration (cell size), but in Advanced E-UTRA, base station devices (cells) with different configurations are in the same area. A communication system based on a mixed network (heterogeneous wireless network, heterogeneous network) is being studied. In addition, E-UTRA is also referred to as LTE (Long Term Evolution), and Advanced E-UTRA is also referred to as LTE-Advanced. In addition, LTE can also be a generic term including LTE-Advanced.

In a communication system in which a cell having a large cell radius (macro cell) and a cell having a cell radius smaller than the macro cell (small cell, small cell) are arranged like a heterogeneous network, a terminal device is used as a macro cell and a small cell. Carrier aggregation (CA) technology and dual connectivity (DC) technology that simultaneously connect to and communicate with each other are defined (Non-Patent Document 1).

On the other hand, in Non-Patent Document 2, Licensed-Assisted Access (LAA) is being studied. In LAA, for example, the unlicensed spectrum used by the wireless LAN (Local Area Network) is used as LTE. Specifically, the non-allocated frequency band is set as a secondary cell (secondary component carrier). The secondary cell used as the LAA is assisted in connection, communication and / or configuration by the primary cell (primary component carrier) configured in the assigned frequency band (Licensed spectrum). LAA expands the frequency band available in LTE, enabling wideband transmission. The LAA is also used in a shared spectrum that is shared between predetermined operators.

In addition, delay in wireless communication is one of the important factors in a system for safety and security. It is important to further reduce the delay in LTE including LTE using LAA and LTE using the conventional allocated frequency band.

3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures (Release 12), 3GPP TS 36.213 V12.4.0 (2014-12). RP-141664, Ericsson, Qualcomm, Huawei, Alcatel-Lucent, “Study on Licensed-Assisted Access using LTE,” 3GPP TSG RAN Meeting # 65, September 2014.

In LAA, if an unallocated or shared frequency band is used, that frequency band will be shared with other systems and / or other operators. However, LTE is designed on the assumption that it will be used in the allocated frequency band or the non-shared frequency band. Therefore, conventional LTE cannot be used in the non-allocated frequency band or the shared frequency band. Further, in LTE including LTE using LAA and LTE using the conventional allocated frequency band, it is required to reduce the delay in wireless communication.

The present invention has been made in view of the above points, and an object of the present invention is a terminal device or base station device capable of efficiently controlling a cell using an allocated frequency band, an unallocated frequency band, or a shared frequency band. , And to provide a communication method.

The terminal device according to one aspect of the present invention is a terminal device (UE) so as to monitor EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type (frame structure type 3). When the terminal device has a set receiver and detects DCI (downlink control information) in the subframe, the terminal device sets the OFDM symbol according to the field included in the DCI in the subframe. Predetermined, the OFDM symbol is used for downlink transmission, and the DMRS (demodulation reference signal) associated with the EPDCCH is mapped within the subframe according to the setting of the OFDM symbol.

The base station device according to one aspect of the present invention is a base station device that communicates with a terminal device (UE) and is an EPDCCH (enhanced physical downlink control) on a serving cell that uses a third frame structure type 3. When the terminal device includes a transmitter set to transmit channel) and detects DCI (downlink control information) in the subframe, the terminal device is included in the DCI in the subframe. The setting of the OFDM symbol is determined according to the field, the OFDM symbol is used for downlink transmission, and the DMRS (demodulation reference signal) associated with the EPDCCH is mapped in the subframe according to the setting of the OFDM symbol.

The communication method of the terminal device according to one aspect of the present invention is the communication method of the terminal device (UE), and is an EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type 3. ) Is included, and when the terminal device detects DCI (downlink control information) in the subframe, the terminal device sets the OFDM symbol according to the field included in the DCI in the subframe. The OFDM symbol is used for downlink transmission, and the DMRS (demodulation reference signal) associated with the EPDCCH is mapped in the subframe according to the setting of the OFDM symbol.

The communication method of the base station device according to one aspect of the present invention is the communication method of the base station device that communicates with the terminal device (UE), and is on a serving cell that uses a third frame structure type 3. When the terminal device detects DCI (downlink control information) in the subframe, the terminal device is included in the DCI in the subframe, including a step of transmitting an EPDCCH (enhanced physical downlink control channel). The setting of the OFDM symbol is determined according to the field, the OFDM symbol is used for downlink transmission, and the DMRS (demodulation reference signal) associated with the EPDCCH is mapped in the subframe according to the setting of the OFDM symbol.

According to the present invention, transmission efficiency can be improved in a wireless communication system in which a base station device and a terminal device communicate with each other.

It is a figure which shows an example of the wireless frame configuration of the downlink which concerns on this embodiment. It is a figure which shows an example of the wireless frame configuration of the uplink which concerns on this embodiment. It is the schematic which shows an example of the block structure of the base station apparatus 2 which concerns on this embodiment. It is a schematic diagram which shows an example of the block structure of the terminal apparatus 1 which concerns on this embodiment. It is a figure which shows an example of the communication procedure in the LAA cell which concerns on this embodiment. It is a figure which shows an example of the communication procedure in the LAA cell which concerns on this embodiment. It is a figure which shows an example of the communication procedure in the LAA cell which concerns on this embodiment. An example of the EREG configuration in one RB pair is shown. It is a figure which shows an example of the structure of DMRS associated with the 2nd EPDCCH used for the 1st partial subframe. It is a figure which shows an example of the structure of DMRS associated with the 2nd EPDCCH used for the 2nd partial subframe.

<First Embodiment>
The first embodiment of the present invention will be described below. Explanation using a communication system (cellular system) in which a base station device (base station, node B, eNB (eNodeB)) and a terminal device (terminal, mobile station, user device, UE (User equipment)) communicate in a cell. To do.

In the description of the present embodiment, the description regarding the downlink includes a downlink in the normal cell and a downlink in the LAA cell. For example, the description of a downlink subframe includes a downlink subframe in a normal cell, a full subframe in a LAA cell, and a partial subframe in a LAA cell.

The main physical channels and physical signals used in EUTRA and Advanced EUTRA will be described. A channel means a medium used for transmitting a signal, and a physical channel means a physical medium used for transmitting a signal. In this embodiment, physical channels can be used synonymously with signals. Physical channels may be added in the future, or their structure or format may be changed or added in EUTRA, and Advanced EUTRA, but any changes or additions will not affect the description of this embodiment.

EUTRA and Advanced EUTRA manage the scheduling of physical channels or physical signals using radio frames. One radio frame is 10 ms, and one radio frame is composed of 10 subframes. Further, one subframe is composed of two slots (that is, one subframe is 1 ms and one slot is 0.5 ms). In addition, resource blocks are used for management as the minimum unit of scheduling in which physical channels are arranged. The resource block is defined by a fixed frequency domain in which the frequency axis is composed of a set of a plurality of subcarriers (for example, 12 subcarriers) and a region in which a constant transmission time interval (1 slot) is formed.

FIG. 1 is a diagram showing an example of a downlink wireless frame configuration according to the present embodiment. The OFDM access method is used for the downlink. In the downlink, PDCCH, EPDCCH, physical downlink shared channel (PDSCH; Physical Downlink Shared Channel) and the like are assigned. The downlink radio frame is composed of a downlink resource block (RB) pair. This downlink RB pair is a unit such as allocation of downlink radio resources, and starts from a frequency band (RB bandwidth) and a time zone (two slots = one subframe) having a predetermined width. Become. One downlink RB pair is composed of two downlink RBs (RB bandwidth x slots) that are continuous in the time domain. One downlink RB is composed of 12 subcarriers in the frequency domain. Further, in the time domain, it is composed of 7 OFDM symbols when a normal cyclic prefix is added, and 6 when a longer cyclic prefix than usual is added. A region defined by one subcarrier in the frequency domain and one OFDM symbol in the time domain is referred to as a resource element (RE; Resource Element). The physical downlink control channel is a physical channel to which downlink control information such as terminal device identifier, physical downlink shared channel scheduling information, physical uplink shared channel scheduling information, modulation method, coding rate, and retransmission parameters is transmitted. Is. Although the downlink subframe in one element carrier (CC; Component Carrier) is described here, the downlink subframe is defined for each CC, and the downlink subframe is almost synchronized between the CCs. ..

Although not shown here, a synchronization signal (Synchronization Signals), a physical broadcast information channel, or a downlink reference signal (RS: Reference Signal, downlink reference signal) may be arranged in the downlink subframe. .. The downlink reference signal includes a cell-specific reference signal (CRS: Cell-specific RS) transmitted on the same transmission port as the PDCCH, and a channel state information reference signal (CSI: Channel State Information) used for measuring channel state information (CSI). CSI-RS), terminal-specific reference signal (URS: UE-specific RS) transmitted on the same transmission port as some PDSCHs, demodulation reference signal (DMRS: Demodulation RS) transmitted on the same transmission port as EPDCCH, etc. There is. Further, it may be a carrier in which CRS is not arranged. At this time, in some subframes (for example, the first and sixth subframes in the radio frame), only some transmission ports of CRS (for example, transmission port 0) are used as signals for tracking time and / or frequency. ) Or a signal similar to the signal corresponding to all transmission ports (referred to as extended synchronization signal) can be inserted. Further, the terminal-specific reference signal transmitted on the same transmission port as some PDSCHs is also referred to as a terminal-specific reference signal or DMRS associated with the PDSCH. The demodulation reference signal transmitted on the same transmission port as the EPDCCH is also referred to as DMRS associated with the EPDCCH.

Although not shown here, a detection signal (DS: Discovery Signal) may be arranged in the downlink subframe. The terminal is set up (configured) with a DMTC (Discovery signals measurement timing configuration) based on the parameters set through RRC signaling. The DMTC Occasion is 6 milliseconds and consists of 6 consecutive subframes. The terminal also assumes that DS is not transmitted to a subframe outside the DMTC Occasion.

In a certain cell, DS (DS Occasion) is composed of a time period (DS period) of a predetermined number of consecutive subframes. The predetermined number is 1 to 5 in FDD (Frame structure type 1) and 2 to 5 in TDD (Frame structure type 2). The predetermined number is set by RRC signaling. The DS period or its setting is also referred to as DMTC (Discovery signals measurement timing configuration). The terminal assumes that the DS is transmitting (mapping, generating) every subframe set by the parameter dmtc-Periodicity set by RRC signaling. Further, in the downlink subframe, the terminal assumes the existence of a DS composed of the following signals.
(1) CRS of antenna port 0 in DwPTS of all downlink subframes and all special subframes during the DS period.
(2) In FDD, PSS in the first subframe of the DS period. In TDD, PSS in the second subframe of that DS period.
(3) SSS in the first subframe of the DS period.
(4) Non-zero power CSI-RS in zero or more subframes during the DS period. The non-zero power CSI-RS is set by RRS signaling.

The terminal makes a measurement based on the set DS. The measurement is performed using CRS in DS or non-zero power CSI-RS in DS. In addition, a plurality of non-zero power CSI-RSs can be set in the settings related to the DS.

The DS and DMTC in the LAA cell can be the same as the DS and DMTC in the FDD. For example, in the LAA cell, the DS period is one of 1 to 5, similar to FDD, and the PSS is present in the first subframe of the DS period. The DS in the LAA cell may be configured differently from the DS in the normal cell. For example, the DS in the LAA cell does not include the CRS. Also, the DS in the LAA cell includes PSS and SSS that can be shifted in the frequency direction.

Also, in the LAA cell, control signals and / or control channels containing control information can be transmitted in subframes within the DS Occasion or subframes within the DMTC Occasion. The control information can include information about the LAA cell. For example, the control information is information about frequency, load, congestion, interference, transmit power, channel occupied time, and / or buffer status for transmit data in the LAA cell.

Also, the control signal and / or control channel can be demodulated or detected by DMRS in the DS Occasion. That is, the control signal and / or control channel is transmitted at the antenna port used to transmit DMRS within the DS Occasion. Specifically, the DMRS in the DS Occasion is a DMRS (demodulation reference signal) associated with its control signal and / or control channel and can be configured similarly to a DMRS associated with a PDSCH or EPDCCH.

Also, the scramble sequence used for the DMRS associated with the control signal and / or the control channel may be generated differently from the scramble sequence used for the DMRS associated with the PDSCH or EPDCCH. Here, the scramble series used for DMRS is generated with values calculated based on the slot number (subframe number), the first parameter, and the second parameter as initial values. For example, in the scramble sequence used for DMRS associated with PDSCH, the first parameter is the cell identifier (cell ID) or the value set by the upper layer and the second parameter is 0 or 1 given by DCI. .. Also, the second parameter is fixed at 0 if not given by DCI. In the scramble series used for DMRS associated with EPDCCH, the first parameter is a value set by the upper layer for each EPDCCH set, and the second parameter is fixed at 2.

In the scramble sequence used for the DMRS associated with the control signal and / or control channel, the first parameter is the value set by the upper layer, the cell identifier of the LAA cell, or the non-zero power in the DS Occasion. It is a cell identifier corresponding to CSI-RS. In the scramble sequence used for DMRS associated with the control signal and / or control channel, the second parameter is a value fixed at a predetermined value or a value set by an upper layer. If the second parameter is fixed at a predetermined value, either a value of 0, 1 or 2 or PDSCH, similar to the second parameter used in the scramble series used for DMRS associated with PDSCH or EPDCCH. Alternatively, it is a value (eg, 3) different from the second parameter used in the scramble series used for DMRS associated with EPDCCH. When the second parameter is set by the upper layer, the second parameter can be set to any value, for example an operator-specific value.

Also, the control signal and / or control channel can be demodulated or detected by the CRS in the DS Occasion. That is, the control signal and / or control channel is transmitted at the antenna port used for transmitting the CRS in the DS Occasion. The scramble sequence used for the CRS in the DS Occasion can be generated based on the first parameter and / or the second parameter described in the scramble sequence used for the DMRS associated with the control signal and / or the control channel. ..

FIG. 2 is a diagram showing an example of an uplink wireless frame configuration according to the present embodiment. The SC-FDMA method is used for the uplink. In the uplink, a physical uplink shared channel (Physical Uplink Shared Channel; PUSCH), PUCCH, and the like are assigned. Further, an uplink reference signal (uplink reference signal) is assigned to a part of PUSCH or PUCCH. The uplink radio frame is composed of an uplink RB pair. This uplink RB pair is a unit for allocating uplink radio resources, etc., from a predetermined width frequency band (RB bandwidth) and time zone (2 slots = 1 subframe). Become. One uplink RB pair is composed of two uplink RBs (RB bandwidth x slots) that are continuous in the time domain. One uplink RB is composed of 12 subcarriers in the frequency domain. In the time domain, it is composed of 7 SC-FDMA symbols when a normal cyclic prefice is added and 6 when a longer than normal cyclic prefice is added. Although the uplink subframe in one CC is described here, the uplink subframe is defined for each CC.

The synchronization signal is composed of three types of primary synchronization signals and a secondary synchronization signal composed of 31 types of codes alternately arranged in the frequency domain, and is based on a combination of the primary synchronization signal and the secondary synchronization signal signals. 504 cell identifiers (Physical Cell Identity (PCI)) that identify the station device and frame timing for wireless synchronization are shown. The terminal device identifies the physical cell ID of the synchronization signal received by the cell search.

The physical broadcast information channel (PBCH; Physical Broadcast Channel) is transmitted for the purpose of notifying (setting) control parameters (broadcast information (system information); System information) commonly used in terminal devices in a cell. The radio resource for which broadcast information is transmitted on the physical downlink control channel is notified to the terminal device in the cell, and the broadcast information not notified on the physical broadcast information channel is transmitted by the physical downlink shared channel in the notified radio resource. A layer 3 message (system information) notifying the broadcast information is transmitted.

As notification information, a cell global identifier (CGI) indicating an identifier for each cell, a tracking area identifier (TAI; Tracking Area Identifier) for managing a standby area by paging, random access setting information (transmission timing timer, etc.), Common radio resource setting information, peripheral cell information, uplink access restriction information, etc. in the cell are notified.

Downlink reference signals are classified into multiple types according to their use. For example, cell-specific RS (Cell-specific reference signals) is a pilot signal transmitted with a predetermined power for each cell, and is a downlink reference signal that is periodically repeated in a frequency domain and a time domain based on a predetermined rule. Is. The terminal device measures the reception quality for each cell by receiving the cell-specific RS. The terminal device also uses the cell-specific RS as a reference signal for demodulating the physical downlink control channel or the physical downlink shared channel transmitted at the same time as the cell-specific RS. As the series used for the cell-specific RS, a series that can be identified for each cell is used.

The downlink reference signal is also used to estimate the downlink propagation path variation. The downlink reference signal used for estimating the propagation path fluctuation is called a channel state information reference signal (CSI-RS). In addition, the downlink reference signal individually set for the terminal device is referred to as UE specific Reference Signals (URS), Demodulation Reference Signal (DMRS) or Distributed RS (DRS), and is an extended physical downlink control channel or It is referred to for channel propagation path compensation processing when demodulating a physical downlink shared channel.

The physical downlink control channel (PDCCH; Physical Downlink Control Channel) is transmitted by several OFDM symbols (for example, 1 to 4 OFDM symbols) from the beginning of each subframe. The extended physical downlink control channel (EPDCCH; Enhanced Physical Downlink Control Channel) is a physical downlink control channel arranged in the OFDM symbol in which the physical downlink shared channel PDSCH is arranged. The PDCCH or EPDCCH is used for the purpose of notifying the terminal device of radio resource allocation information according to the scheduling of the base station device and information indicating an adjustment amount of increase / decrease in transmission power. Hereinafter, when simply referred to as a physical downlink control channel (PDCCH), it means both physical channels of PDCCH and EPDCCH unless otherwise specified.

The terminal device monitors (monitors) the physical downlink control channel addressed to its own device before transmitting and receiving the layer 2 message and the layer 3 message (paging, handover command, etc.) which are downlink data and upper layer control information. By receiving the physical downlink control channel addressed to the own device, it is necessary to acquire radio resource allocation information called uplink grant (downlink assignment) at the time of transmission and downlink grant (downlink assignment) at the time of reception from the physical downlink control channel. is there. In addition to being transmitted with the above-mentioned OFDM symbol, the physical downlink control channel may be configured to be transmitted in the area of the resource block individually assigned to the terminal device from the base station device. It is possible.

The physical uplink control channel (PUCCH; Physical Uplink Control Channel) is an acknowledgment (HARQ-ACK; Hybrid Automatic Repeat feedback / ACKNogue It is used to perform Acknowledgment (), downlink propagation path (channel state) information (CSI; Channel State Information), and uplink radio resource allocation request (radio resource request, scheduling request (SR)).

CSI includes a reception quality index (CQI: Channel Quality Indicator), a recording matrix index (PMI: Precoding Matrix Indicator), a recording type index (PTI: Precoding Type Indicator), and a rank index (RI: Rank Indicator), respectively. Can be used to specify (represent) a suitable modulation scheme and code rate, a suitable pre-recording matrix, a suitable PMI type, and a suitable rank. Each Indicator may be referred to as Indication. Further, for CQI and PMI, wideband CQI and PMI assuming transmission using all resource blocks in one cell and a part of continuous resource blocks (subbands) in one cell were used. It is classified into subbands CQI and PMI that are supposed to be transmitted. Further, the PMI expresses one suitable pre-recording matrix by using two types of PMIs, the first PMI and the second PMI, in addition to the usual type PMI in which one PMI expresses one suitable pre-recording matrix. There is a type of PMI that does.

The physical downlink shared channel (PDSCH; Physical Downlink Shared Channel) is also used to notify the terminal device of downlink data as well as notification information (system information) that is not notified by paging or the physical notification information channel as a layer 3 message. Will be done. The radio resource allocation information of the physical downlink shared channel is indicated by the physical downlink control channel. The physical downlink shared channel is arranged and transmitted in an OFDM symbol other than the OFDM symbol in which the physical downlink control channel is transmitted. That is, the physical downlink shared channel and the physical downlink control channel are time-division-multiplexed within one subframe.

The physical uplink shared channel (PUSCH) mainly transmits uplink data and uplink control information, and can also include uplink control information such as CSI and ACK / NACK. In addition to the uplink data, it is also used to notify the base station device from the terminal device of the layer 2 message and the layer 3 message which are the upper layer control information. Further, as with the downlink, the radio resource allocation information of the physical uplink shared channel is indicated by the physical downlink control channel.

The uplink reference signal (uplink reference signal; also referred to as Uplink Reference Signal, uplink pilot signal, uplink pilot channel) is a physical uplink control channel PUCCH and / or a physical uplink shared channel PUSCH by the base station apparatus. Includes a demodulation reference signal (DMRS) used for demodulation and a sounding reference signal (SRS) used by the base station device primarily to estimate the uplink channel state. Is done. Further, the sounding reference signal includes a periodic sounding reference signal (Periodic SRS) transmitted periodically and an aperiodic sounding reference signal (Aperiodic SRS) transmitted when instructed by the base station apparatus. ..

A physical random access channel (PRACH) is a channel used to notify (set) a preamble sequence and has a guard time. The preamble sequence is configured to notify the base station apparatus of information by a plurality of sequences. For example, when 64 types of sequences are prepared, 6-bit information can be presented to the base station apparatus. The physical random access channel is used as a means of accessing the base station device of the terminal device.

The terminal device has transmission timing adjustment information (timing) required for the uplink radio resource request when the physical uplink control channel is not set for the SR, or for matching the uplink transmission timing with the reception timing window of the base station device. A physical random access channel is used, for example, to request a base station device to advance (also called a Timing Advance (TA) command). The base station apparatus can also request the terminal apparatus to start a random access procedure using a physical downlink control channel.

Layer 3 messages are messages handled by the protocol of the control plane (CP (Control-plane, C-Plane)) exchanged between the RRC (radio resource control) layer of the terminal device and the base station device, and are handled by RRC signaling or RRC. Can be used synonymously with message. A protocol that handles user data (uplink data and downlink data) with respect to the control plane is referred to as a user plane (UP (User-plane, U-Plane)). Here, the transport block, which is the transmission data in the physical layer, includes the C-Plane message and the U-Plane data in the upper layer. For other physical channels, detailed description will be omitted.

The communicable range (communication area) of each frequency controlled by the base station apparatus is regarded as a cell. At this time, the communication area covered by the base station apparatus may have a different width and a different shape for each frequency. Further, the area to be covered may be different for each frequency. A wireless network in which cells having different types of base station devices and different cell radii sizes are mixed in areas of the same frequency and / or different frequencies to form one communication system is called a heterogeneous network. ..

The terminal device operates by regarding the inside of the cell as a communication area. When the terminal device moves from one cell to another, it moves to another appropriate cell by the cell reselection procedure during non-wireless connection (during non-communication) and by the handover procedure during wireless connection (during communication). To do. An appropriate cell is a cell that is generally judged not to be prohibited from accessing the terminal device based on the information specified by the base station device, and the downlink reception quality satisfies a predetermined condition. Indicates the cell to be used.

Further, the terminal device and the base station device aggregate (aggregate) the frequencies (component carriers or frequency bands) of a plurality of different frequency bands (frequency bands) by carrier aggregation into one frequency (frequency band). You may apply the technique to treat as. The component carrier includes an uplink component carrier corresponding to an uplink and a downlink component carrier corresponding to a downlink. In the present specification, frequency and frequency band may be used synonymously.

For example, when five component carriers having a frequency bandwidth of 20 MHz are aggregated by carrier aggregation, a terminal device capable of carrier aggregation regards these as a frequency bandwidth of 100 MHz and transmits / receives them. The component carriers to be aggregated may have continuous frequencies or frequencies in which all or part of them are discontinuous. For example, when the usable frequency bands are 800 MHz band, 2 GHz band, and 3.5 GHz band, one component carrier is transmitted in the 800 MHz band, another component carrier is transmitted in the 2 GHz band, and another component carrier is transmitted in the 3.5 GHz band. May be.

It is also possible to aggregate a plurality of continuous or discontinuous component carriers in the same frequency band. The frequency bandwidth of each component carrier may be a frequency bandwidth narrower (for example, 5 MHz or 10 MHz) than the receivable frequency bandwidth of the terminal device (for example, 20 MHz), or the frequency bandwidth to be aggregated may be different. .. The frequency bandwidth is preferably equal to one of the frequency bandwidths of the conventional cell in consideration of backward compatibility, but may be different from the frequency bandwidth of the conventional cell.

In addition, component carriers (carrier types) that are not backward compatible may be aggregated. It is desirable that the number of uplink component carriers assigned (set or added) by the base station device to the terminal device is the same as or smaller than the number of downlink component carriers.

A cell composed of an uplink component carrier in which an uplink control channel is set for a radio resource request and a downlink component carrier that is uniquely connected to the uplink component carrier is a primary cell (PCell: Primary cell). ). Further, a cell composed of component carriers other than the primary cell is referred to as a secondary cell (SCell: Secondary cell). The terminal device receives the paging message in the primary cell, detects the update of the broadcast information, performs the initial access procedure, sets the security information, and the like, but may not perform these in the secondary cell.

The primary cell is out of the control of activation and deactivation (that is, it is always considered to be activated), but the secondary cell is in a state of activation and deactivation. In addition to being explicitly specified by the base station device, these state changes are changed based on a timer set in the terminal device for each component carrier. The primary cell and the secondary cell are collectively called a serving cell (area cell).

Note that carrier aggregation is communication by a plurality of cells using a plurality of component carriers (frequency bands), and is also referred to as cell aggregation. The terminal device may be wirelessly connected to the base station device via a relay station device (or repeater) for each frequency. That is, the base station apparatus of this embodiment can be replaced with a relay station apparatus.

The base station apparatus manages cells, which are areas in which the terminal apparatus can communicate with the base station apparatus, for each frequency. One base station device may manage a plurality of cells. The cells are classified into a plurality of types according to the size (cell size) of the area in which the terminal device can communicate. For example, cells are classified into macro cells and small cells. Further, small cells are classified into femtocells, picocells, and nanocells according to the size of the area. Further, when the terminal device can communicate with a certain base station device, among the cells of the base station device, the cell set to be used for communication with the terminal device is a service cell. Cells that are present and are not used for other communications are referred to as peripheral cells.

In other words, in carrier aggregation (also referred to as carrier aggregation), the set serving cells include one primary cell and one or more secondary cells.

The primary cell is a serving cell in which the initial connection construction procedure is performed, a serving cell in which the connection reconstruction procedure is started, or a cell designated as the primary cell in the handover procedure. The primary cell operates at the primary frequency. Secondary cells may be set up when or after the connection is (re) established. The secondary cell operates at the secondary frequency. The connection may be referred to as an RRC connection. It is aggregated in one primary cell and one or more secondary cells for a terminal device that supports CA.

In this embodiment, LAA (Licensed Assisted Access) is used. In LAA, the primary cell is set (used) with an assigned frequency and at least one of the secondary cells is set with an unassigned frequency. The secondary cell for which the non-allocated frequency is set is assisted from the primary cell or secondary cell for which the allocated frequency is set. For example, a primary cell or secondary cell in which an allocated frequency is set can be set and / or controlled by RRC signaling, MAC signaling, and / or PDCCH signaling to a secondary cell in which an unallocated frequency is set. Notify. In the present embodiment, the cell assisted from the primary cell or the secondary cell is also referred to as a LAA cell. LAA cells can be aggregated (assisted) by carrier aggregation with primary and / or secondary cells. Further, the primary cell or the secondary cell that assists the LAA cell is also referred to as an assist cell. Further, the cell in which the assigned frequency is set is also called a normal cell (conventional cell), and the subframe in the normal cell is also called a normal subframe (conventional subframe). Normal subframes include downlink subframes, uplink subframes, and special subframes. In the present embodiment, the normal subframe will be described separately from the subframe used in the LAA cell.

LAA cells may be aggregated (assisted) by dual connectivity with primary and / or secondary cells.

The basic structure (architecture) of dual connectivity will be described below. For example, a case where the terminal device 1 is connected to a plurality of base station devices 2 (for example, base station device 2-1 and base station device 2-2) at the same time will be described. It is assumed that the base station apparatus 2-1 is a base station apparatus constituting a macro cell, and the base station apparatus 2-2 is a base station apparatus constituting a small cell. Such connection of the terminal device 1 using a plurality of cells belonging to the plurality of base station devices 2 at the same time is referred to as dual connectivity. The cells belonging to each base station device 2 may be operated at the same frequency or may be operated at different frequencies.

Carrier aggregation differs from dual connectivity in that a plurality of cells are managed by one base station device 2 and the frequencies of the cells are different. In other words, carrier aggregation is a technique for connecting one terminal device 1 and one base station device 2 via a plurality of cells having different frequencies, whereas dual connectivity is one terminal device 1. This is a technique for connecting a plurality of base station devices 2 and a plurality of base station devices 2 via a plurality of cells having the same or different frequencies.

The terminal device 1 and the base station device 2 can apply the technology applied to carrier aggregation to dual connectivity. For example, the terminal device 1 and the base station device 2 may apply techniques such as primary cell and secondary cell allocation, activation / deactivation, etc. to cells connected by dual connectivity.

In dual connectivity, the base station apparatus 2-1 or the base station apparatus 2-2 is connected to the MME and the SGW by a backbone line. The MME is a higher-level control station device corresponding to the MME (Mobile Management Entry), and plays a role of setting the mobility management and authentication control (security control) of the terminal device 1 and the route of user data to the base station device 2. Have. The SGW is a higher-level control station device corresponding to the Serving Gateway (S-GW), and has a role of transmitting user data according to a user data path to the terminal device 1 set by the MME.

Further, in dual connectivity, the connection path between the base station device 2-1 or the base station device 2-2 and the SGW is referred to as an SGW interface. Further, the connection path between the base station device 2-1 or the base station device 2-2 and the MME is referred to as an MME interface. Further, the connection path between the base station device 2-1 and the base station device 2-2 is referred to as a base station interface. The SGW interface is also referred to as the S1-U interface in EUTRA. The MME interface is also referred to as an S1-MME interface in EUTRA. The base station interface is also referred to as an X2 interface in EUTRA.

An example of an architecture that realizes dual connectivity will be described. In dual connectivity, the base station apparatus 2-1 and the MME are connected by an MME interface. Further, the base station device 2-1 and the SGW are connected by an SGW interface. Further, the base station apparatus 2-1 provides a communication path with the MME and / or the SGW to the base station apparatus 2-2 via the base station interface. In other words, the base station apparatus 2-2 is connected to the MME and / or the SGW via the base station apparatus 2-1.

It also describes another example of another architecture that achieves dual connectivity. In dual connectivity, the base station apparatus 2-1 and the MME are connected by an MME interface. Further, the base station device 2-1 and the SGW are connected by an SGW interface. The base station apparatus 2-1 provides a communication path with the MME to the base station apparatus 2-2 via the base station interface. In other words, the base station device 2-2 is connected to the MME via the base station device 2-1. Further, the base station apparatus 2-2 is connected to the SGW via the SGW interface.

The base station apparatus 2-2 and the MME may be directly connected by the MME interface.

From another point of view, dual connectivity refers to radio resources provided by at least two different network points (master base station equipment (MeNB: Master eNB) and secondary base station equipment (SeNB: Secondary eNB)). This is an operation consumed by the terminal device. In other words, dual connectivity means that the terminal device makes an RRC connection at at least two network points. In dual connectivity, the terminal devices may be connected in an RRC connection (RRC_CONNECTED) state and by a non-ideal backhaul.

In dual connectivity, a base station device that is connected to at least S1-MME and acts as a mobility anchor for the core network is called a master base station device. Further, a base station device that is not a master base station device that provides additional radio resources to a terminal device is referred to as a secondary base station device. When the group of serving cells associated with the master base station apparatus is referred to as a master cell group (MCG: Master Cell Group), and the group of serving cells associated with the secondary base station apparatus is referred to as a secondary cell group (SCG: Secondary Cell Group). There is also. The cell group may be a serving cell group.

In dual connectivity, the primary cell belongs to the MCG. Further, in SCG, a secondary cell corresponding to a primary cell is referred to as a primary secondary cell (pSCell: Primary Secondary Cell). The pS Cell may be referred to as a special cell or a special secondary cell (Special Cell: Special Secondary Cell). The special SCell (base station device constituting the special SCell) may support a part of the functions of the PCell (base station device constituting the PCell) (for example, a function of transmitting and receiving PUCCH). In addition, pSCell may support only some functions of PCell. For example, pSCell may support the ability to transmit PDCCH. Further, the pS Cell may support a function of performing PDCCH transmission using a search space different from CSS or USS. For example, a search space different from USS is based on a search space determined based on a value specified in the specifications, a search space determined based on RNTI different from C-RNTI, and a value set in a higher layer different from RNTI. It is a search space determined by. Further, the pSCell may always be in the activated state. Further, pSCell is a cell capable of receiving PUCCH.

In dual connectivity, the Data Radio Bearer (DRB) may be assigned individually to the MeNB and SeNB. On the other hand, the signaling radio bearer (SRB: Signaling Radio Bearer) may be assigned only to the MeNB. In dual connectivity, the duplex mode may be set individually for MCG and SCG or PCell and pSCell. In dual connectivity, MCG and SCG or PCell and pSCell do not have to be synchronized. In the dual connectivity, a plurality of parameters (TAG: Timing Advance Group) for timing adjustment may be set in each of the MCG and the SCG. That is, the terminal device can perform uplink transmission at a plurality of different timings within each CG.

In the dual connectivity, the terminal device can transmit the UCI corresponding to the cell in the MCG only to the MeNB (PCell), and the UCI corresponding to the cell in the SCG can be transmitted only to the SeNB (pSCell). For example, UCI is SR, HARQ-ACK, and / or CSI. Further, in each UCI transmission, the transmission method using PUCCH and / or PUSCH is applied in each cell group.

All signals can be transmitted and received in the primary cell, but some signals cannot be transmitted and received in the secondary cell. For example, PUCCH (Physical Uplink Control Channel) is transmitted only in the primary cell. Further, the PRACH (Physical Random Access Channel) is transmitted only in the primary cell unless a plurality of TAGs (Timing Advance Groups) are set between the cells. Further, PBCH (Physical Broadcast Channel) is transmitted only in the primary cell. Further, the MIB (Master Information Block) is transmitted only in the primary cell. In the primary secondary cell, signals that can be transmitted and received in the primary cell are transmitted and received. For example, PUCCH may be transmitted in the primary secondary cell. Further, the PRACH may be transmitted in the primary secondary cell regardless of whether a plurality of TAGs are set. Further, PBCH and MIB may be transmitted in the primary and secondary cells.

In the primary cell, RLF (Radio Link Failure) is detected. The secondary cell does not recognize that RLF has been detected even if the conditions for detecting RLF are met. In the primary and secondary cells, RLF is detected if the conditions are met. When RLF is detected in the primary secondary cell, the upper layer of the primary secondary cell notifies the upper layer of the primary cell that RLF has been detected. In the primary cell, SPS (Semi-Persistence Scheduling) or DRX (Discontinuus Reception) may be performed. The secondary cell may perform the same DRX as the primary cell. In the secondary cell, the information / parameters related to the MAC settings are basically shared with the primary cell / primary secondary cell of the same cell group. Some parameters (eg, sTAG-Id) may be set for each secondary cell. Some timers and counters may only be applied to the primary cell and / or the primary secondary cell. Timers and counters that apply only to secondary cells may be set.

In an example in which dual connectivity is applied to the LAA cell, the MCG (base station device 2-1) constitutes the base station device that constitutes the primary cell, and the SCG (base station device 2-2) constitutes the LAA cell. It is a base station device. That is, the LAA cell is set as the pSCell of the SCG.

In another example where dual connectivity is applied to the LAA cell, the MCG is the base station apparatus constituting the primary cell, and the SCG is the base station apparatus constituting the pS Cell and the LAA cell. That is, the LAA cell is assisted from the pSCell in the SCG. When a secondary cell is further set in the SCG, the LAA cell may be assisted from the secondary cell.

In another example where dual connectivity is applied to the LAA cell, the MCG is the base station apparatus constituting the primary cell and the LAA cell, and the SCG is the base station apparatus constituting the pS Cell. That is, the LAA cell is assisted from the primary cell in the MCG. When a secondary cell is further set in the MCG, the LAA cell may be assisted from the secondary cell.

FIG. 3 is a schematic view showing an example of the block configuration of the base station apparatus 2 according to the present embodiment. The base station apparatus 2 includes an upper layer (upper layer control information notification unit, upper layer processing unit) 501, a control unit (base station control unit) 502, a code word generation unit 503, a downlink subframe generation unit 504, and an OFDM signal transmission. Unit (downlink transmission unit) 506, transmission antenna (base station transmission antenna) 507, reception antenna (base station reception antenna) 508, SC-FDMA signal reception unit (CSI reception unit) 509, uplink subframe processing unit 510. Have. The downlink subframe generation unit 504 has a downlink reference signal generation unit 505. Further, the uplink subframe processing unit 510 has an uplink control information extraction unit (CSI acquisition unit) 511.

FIG. 4 is a schematic view showing an example of the block configuration of the terminal device 1 according to the present embodiment. The terminal device 1 includes a receiving antenna (terminal receiving antenna) 601, an OFDM signal receiving unit (downlink receiving unit) 602, a downlink subframe processing unit 603, a transport block extraction unit (data extraction unit) 605, and a control unit (terminal). Control unit) 606, upper layer (upper layer control information acquisition unit, upper layer processing unit) 607, channel state measurement unit (CSI generation unit) 608, uplink subframe generation unit 609, SC-FDMA signal transmission unit (UCI transmission) Part) 611 and 612, and transmitting antennas (terminal transmitting antennas) 613 and 614. The downlink subframe processing unit 603 has a downlink reference signal extraction unit 604. Further, the uplink subframe generation unit 609 has an uplink control information generation unit (UCI generation unit) 610.

First, the flow of transmitting and receiving downlink data will be described with reference to FIGS. 3 and 4. In the base station apparatus 2, the control unit 502 includes MCS (Modulation and Coding Process) indicating the modulation method and coding rate in the downlink, downlink resource allocation indicating the RB used for data transmission, and information used for controlling HARQ (). The redundancy version, HARQ process number, new data index) are held, and the code word generation unit 503 and the downlink subframe generation unit 504 are controlled based on these. The downlink data (also referred to as the downlink transport block) sent from the upper layer 501 is subjected to processing such as error correction coding and rate matching processing under the control of the control unit 502 in the code word generation unit 503. It is applied and a code word is generated. Up to two codewords are transmitted simultaneously in one subframe in one cell. In the downlink subframe generation unit 504, the downlink subframe is generated according to the instruction of the control unit 502. First, the codeword generated by the codeword generation unit 503 is converted into a modulation symbol sequence by modulation processing such as PSK (Phase Shift Keying) modulation or QAM (Quadrature Amplitude Modulation) modulation. Further, the modulation symbol sequence is mapped to RE in a part of the RB, and the downlink subframe for each antenna port is generated by the pre-recording process. At this time, the transmission data series sent from the upper layer 501 includes upper layer control information which is control information in the upper layer (for example, dedicated (individual) RRC (Radio Resource Control) signaling). Further, the downlink reference signal generation unit 505 generates a downlink reference signal. The downlink subframe generation unit 504 maps the downlink reference signal to the RE in the downlink subframe according to the instruction of the control unit 502. The downlink subframe generated by the downlink subframe generation unit 504 is modulated into an OFDM signal by the OFDM signal transmission unit 506 and transmitted via the transmission antenna 507. Although the configuration in which the OFDM signal transmission unit 506 and the transmission antenna 507 are provided one by one is illustrated here, when the downlink subframe is transmitted using a plurality of antenna ports, the OFDM signal transmission unit 506 and the transmission are transmitted. It may be configured to have a plurality of antennas 507. Further, the downlink subframe generation unit 504 can also have an ability to generate a downlink control channel of a physical layer such as PDCCH or EPDCCH and map it to RE in the downlink subframe. The plurality of base station devices (base station device 2-1 and base station device 2-2) each transmit individual downlink subframes.

In the terminal device 1, the OFDM signal is received by the OFDM signal receiving unit 602 via the receiving antenna 601 and subjected to the OFDM demodulation processing. The downlink subframe processing unit 603 first detects the downlink control channel of the physical layer such as PDCCH or EPDCCH. More specifically, the downlink subframe processing unit 603 decodes the PDCCH or EPDCCH as if it was transmitted in the area where the PDCCH or EPDCCH can be assigned, and confirms the CRC (Cyclic Redundancy Check) bit added in advance. (Blind decoding). That is, the downlink subframe processing unit 603 monitors PDCCH and EPDCCH. One CRC bit is assigned to one terminal such as an ID (C-Radio Network Identifier) and SPS-C-RNTI (Semi Persistence Scheduling-C-RNTI) assigned in advance from the base station apparatus. If it matches the terminal unique identifier or the Rotary C-RNTI), the downlink subframe processing unit 603 recognizes that the PDCCH or EPDCCH has been detected, and uses the control information contained in the detected PDCCH or EPDCCH to use the PDSCH. Take out. The control unit 606 holds information used for controlling HARQ, such as MCS indicating the modulation method and coding rate in the downlink based on the control information, downlink resource allocation indicating the RB used for downlink data transmission, and based on these. It controls the downlink subframe processing unit 603, the transport block extraction unit 605, and the like. More specifically, the control unit 606 controls the downlink subframe generation unit 504 to perform RE mapping processing, RE demapping processing, demodulation processing, and the like corresponding to the modulation processing. The PDSCH extracted from the received downlink subframe is sent to the transport block extraction unit 605. Further, the downlink reference signal extraction unit 604 in the downlink subframe processing unit 603 extracts the downlink reference signal from the downlink subframe. In the transport block extraction unit 605, rate matching processing in the code word generation unit 503, rate matching processing corresponding to error correction coding, error correction decoding, etc. are performed, and the transport block is extracted and sent to the upper layer 607. Be done. The transport block includes upper layer control information, and the upper layer 607 informs the control unit 606 of necessary physical layer parameters based on the upper layer control information. The plurality of base station devices 2 (base station device 2-1 and base station device 2-2) each transmit individual downlink subframes, and the terminal device 1 receives these. The processing may be performed for each of the downlink subframes for each of the plurality of base station devices 2. At this time, the terminal device 1 may or may not recognize that the plurality of downlink subframes are transmitted from the plurality of base station devices 2. If not recognized, the terminal device 1 may simply recognize that a plurality of downlink subframes are transmitted in the plurality of cells. Further, the transport block extraction unit 605 determines whether or not the transport block can be detected correctly, and the determination result is sent to the control unit 606.

Next, the flow of transmitting and receiving uplink signals will be described. In the terminal device 1, under the instruction of the control unit 606, the downlink reference signal extracted by the downlink reference signal extraction unit 604 is sent to the channel state measurement unit 608, and the channel state and / or interference in the channel state measurement unit 608. Is measured, and the CSI is calculated based on the measured channel condition and / or interference. Further, the control unit 606 informs the uplink control information generation unit 610 of HARQ-ACK (DTX (not transmitted), ACK (successful detection) or NACK (DTX (successful detection)) based on the determination result of whether or not the transport block can be detected correctly. Instructs the generation of (detection failure)) and mapping to downlink subframes. The terminal device 1 performs these processes for each of the downlink subframes for each of the plurality of cells. The uplink control information generation unit 610 generates a PUCCH containing the calculated CSI and / or HARQ-ACK. In the uplink subframe generation unit 609, the PUSCH including the uplink data sent from the upper layer 607 and the PUCCH generated in the uplink control information generation unit 610 are mapped to the RB in the uplink subframe, and the uplink is linked. A subframe is generated. The uplink subframe is subjected to SC-FDMA modulation at the SC-FDMA signal transmission unit 611 to generate an SC-FDMA signal, and is transmitted via the transmission antenna 613.

The details of the LAA cell will be described below.

The frequency used by the LAA cell is shared with other communication systems and / or other LTE operators. In frequency sharing, LAA cells need to be fair with other communication systems and / or other LTE operators. For example, in the communication method used in the LAA cell, a fair frequency sharing technique (method) is required. In other words, the LAA cell is a cell that performs a communication method (communication procedure) to which a fair frequency sharing technology can be applied (used).

An example of a fair frequency sharing technology is LBT (Listen-Before-Talk). The LBT transmits interference power (interference signal, reception power, reception signal, noise power, noise signal), etc. of a certain base station or terminal before transmitting a signal using a certain frequency (component carrier, cell). By measuring (detecting), the frequency is either idle (free, crowded, Presence, Occupied) or busy (not free, not crowded, Absence, Identify (detect, assume, determine) whether it is Clear). If it is determined based on the LBT that the frequency is idle, the LAA cell can transmit a signal at a predetermined timing at that frequency. If, based on the LBT, the frequency is determined to be busy, the LAA cell does not transmit a signal at a given timing at that frequency. The LBT can be controlled so as not to interfere with signals transmitted by other base stations and / or terminals, including other communication systems and / or other LTE operators.

The LBT procedure is defined as a mechanism by which a base station or terminal applies a CCA check before using its frequency (channel). The CCA performs power detection or signal detection to determine the presence or absence of other signals in the channel to identify whether the frequency is idle or busy. In this embodiment, the definition of CCA may be equivalent to the definition of LBT.

In CCA, various methods can be used as a method for determining the presence or absence of other signals. For example, CCA determines based on whether the interfering power at a frequency exceeds a threshold. Also, for example, the CCA is determined based on whether the received power of a given signal or channel at a given frequency exceeds a certain threshold. The threshold may be predetermined. The threshold may be set from a base station or other terminal. The threshold value may be determined (set) at least based on other values (parameters) such as transmit power (maximum transmit power).

The CCA in the LAA cell does not need to be recognized by the terminal connected (set) to the LAA cell.

The LAA cell may be defined as a cell different from the secondary cell that uses the assigned frequency. For example, the LAA cell is set differently than the setting of the secondary cell using the assigned frequency. Some of the parameters set in the LAA cell are not set in the secondary cell that uses the assigned frequency. Some of the parameters set in the secondary cell using the assigned frequency are not set in the LAA cell. In the present embodiment, the LAA cell is described as a cell different from the primary cell and the secondary cell, but the LAA cell may be defined as one of the secondary cells. The conventional secondary cell is also referred to as a first secondary cell, and the LAA cell is also referred to as a second secondary cell. The conventional primary cell and secondary cell are also referred to as a first serving cell, and the LAA cell is also referred to as a second serving cell.

Further, the LAA cell may be different from the conventional frame configuration type. For example, a conventional serving cell uses (sets) a first frame structure type (FDD, frame structure type 1) or a second frame structure type (TDD, frame structure type 2), whereas a LAA cell does not. A third frame structure type 3 is used (set).

Here, the unassigned frequency is a frequency different from the assigned frequency assigned as the exclusive frequency to a predetermined operator. For example, the unassigned frequency is the frequency used by the wireless LAN. Further, for example, the non-allocated frequency is a frequency that cannot be set in the conventional LTE, and the allocated frequency is a frequency that can be set in the conventional LTE. In the present embodiment, the frequency set in the LAA cell will be described as an unassigned frequency, but the frequency is not limited thereto. That is, the unassigned frequency can be replaced with the frequency set in the LAA cell. For example, the unassigned frequency is a frequency that cannot be set in the primary cell and is a frequency that can be set only in the secondary cell. For example, unassigned frequencies also include frequencies shared by multiple operators. Further, for example, the unassigned frequency is a frequency set only in a cell that is set, assumed, and / or processed differently from the conventional primary cell or secondary cell.

The LAA cell can be a cell that uses a method different from the conventional method in terms of configuration and communication procedure of radio frames, physical signals, and / or physical channels in LTE.

For example, in the LAA cell, the predetermined signal and / or channel set (transmitted) in the primary cell and / or the secondary cell is not set (transmitted). The predetermined signal and / or channel includes CRS, DS, PDCCH, EPDCCH, PDSCH, PSS, SSS, PBCH, PHICH, PCFICH, CSI-RS and / or SIB and the like. For example, the signals and / or channels that are not set in the LAA cell are: The signals and / or channels described below may be used in combination. In the present embodiment, the signal and / or channel not set in the LAA cell may be read as a signal and / or channel that the terminal does not expect to transmit from the LAA cell.
(1) In the LAA cell, the control information of the physical layer is not transmitted by PDCCH, but is transmitted only by EPDCCH.
(2) In the LAA cell, CRS, DMRS, URS, PDCCH, EPDCCH and / or PDSCH are not transmitted in all subframes even in the activated (on) subframe, and the terminal transmits in all subframes. Do not assume that it has been done.
(3) In the LAA cell, the terminal assumes that DRS, PSS, and / or SSS are being transmitted in the activated (on) subframe.
(4) In the LAA cell, the terminal is notified of information on CRS mapping for each subframe, and assumes CRS mapping based on the information. For example, CRS mapping assumptions are not mapped to all resource elements in that subframe. CRS mapping assumptions are not mapped to some resource elements in that subframe (eg, all resource elements in the first 2 OFDM symbols). CRS mapping assumptions are mapped to all resource elements in that subframe. Further, for example, the information regarding the mapping of CRS is notified from the LAA cell or a cell different from the LAA cell. Information about the mapping of CRS is contained in DCI and is notified by PDCCH or EPDCCH.

Further, for example, in the LAA cell, a predetermined signal and / or channel that is not set (transmitted) in the primary cell and / or the secondary cell is set (transmitted).

Also, for example, in a LAA cell, only downlink component carriers or subframes are defined and only downlink signals and / or channels are transmitted. That is, in the LAA cell, uplink component carriers or subframes are not defined and uplink signals and / or channels are not transmitted.

Further, for example, in the LAA cell, the corresponding DCI (Downlink Control Information) format is different from the DCI format corresponding to the primary cell and / or the secondary cell. A DCI format that supports only LAA cells is defined. The DCI format corresponding to the LAA cell contains control information that is valid only for the LAA cell.

Further, for example, in the LAA cell, the assumption of the signal and / or the channel is different from that of the conventional secondary cell.

First, the assumption of the signal and / or channel in the conventional secondary cell will be described. Terminals that meet some or all of the following conditions are PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS and / or CSI-RS as their secondary cells, except for DS transmission. Suppose it may not be sent by. The terminal also assumes that the DS is always being transmitted by its secondary cell. Further, the assumption continues until the subframe in which the activation command (command for activation) is received in the secondary cell at a certain carrier frequency of the terminal.
(1) The terminal supports settings (parameters) related to DS.
(2) The RRM measurement based on the DS is set in the secondary cell of the terminal.
(3) The secondary cell is deactivated (deactivated state).
(4) The terminal is not set to receive MBMS by the upper layer in its secondary cell.

In addition, when the secondary cell is activated (activated state), the terminal has PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, in the set predetermined subframe or all subframes. It is assumed that EPDCCH, PHICH, DMRS and / or CSI-RS are transmitted by its secondary cell.

Next, an example of assuming a signal and / or a channel in the LAA cell will be described. Terminals that meet some or all of the following conditions, including DS transmission, have PSS, SSS, PBCH, CRS, PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS and / or CSI-RS in their LAA cells. Suppose it may not be sent by. Further, the assumption continues until the subframe in which the activation command (command for activation) is received in the secondary cell at a certain carrier frequency of the terminal.
(1) The terminal supports settings (parameters) related to DS.
(2) In the LAA cell of the terminal, DS-based RRM measurement is set.
(3) The LAA cell is deactivated (deactivated state).
(4) The terminal is not set to receive MBMS by the upper layer in its LAA cell.

Also, another example of signal and / or channel assumptions in the LAA cell will be described. When the LAA cell is deactivated, the signal and / or channel assumptions in the LAA cell are the same as the signal and / or channel assumptions in the conventional secondary cell. When the LAA cell is activated, the signal and / or channel assumptions in the LAA cell are different from the signal and / or channel assumptions in the conventional secondary cell. For example, if the LAA cell is activated, the terminal will have PSS, SSS, PBCH, CRS, except that the LAA cell has a predetermined subframe set in the LAA cell. It is assumed that PCFICH, PDSCH, PDCCH, EPDCCH, PHICH, DMRS and / or CSI-RS may not be transmitted. The details will be described later.

Next, the details of the communication procedure in the LAA cell will be described. In the LAA cell, the transmission of the channel and / or the signal can be started at a timing independent of the subframe boundary based on the LBT. Further, in the LAA cell, the transmission of the channel and / or the signal can be completed at a timing independent of the subframe boundary based on the LBT and the maximum burst length that can be transmitted. That is, channels and / or signals can be transmitted in subframes. Subframes can be defined, for example, as follows: Here, in the present embodiment, the transmittable OFDM symbol indicated by the partial subframe can be defined as assuming that the terminal transmits each or all of the channel and / or the signal.
(1) In a certain subframe, an area from the OFDM symbol in the middle of the subframe to the last OFDM symbol (boundary of the subframe) of the subframe can be transmitted. In this embodiment, it is also referred to as a first partial subframe.
(2) In a certain subframe, an area from the first OFDM symbol (subframe boundary) of the subframe to the OFDM symbol in the middle of the subframe can be transmitted. In this embodiment, it is also referred to as a second subframe.
(3) In a certain subframe, an area from the OFDM symbol in the middle of the subframe to the OFDM symbol in the middle of the subframe can be transmitted. In this embodiment, it is also referred to as a third subframe.

Further, in the partial subframe, the number of OFDM symbols in the middle of the subframe can be limited to a predetermined number. For example, the predetermined number is 2, 3 and / or 4.

When the predetermined number is 2, for example, it can be either 1 slot or 1 subframe (2 slots). That is, the unit of the second EPDCCH in the time direction is one slot or one subframe. When the unit in the time direction of the second EPDCCH is one slot, the unit in the time direction of the PDSCH scheduled by the second EPDCCH can also be one slot. In other words, a communication method (method) in which one subframe is used as a unit as in the conventional LTE and a communication method in which one slot, which is half of the conventional LTE, is used as a unit, are switched and used. By using one slot as a unit, it is possible to reduce the delay in wireless communication. As a result, in addition to the communication method similar to the conventional LTE, a communication method capable of further realizing a communication method capable of reducing the delay in wireless communication becomes possible. This applies not only to LAA cells, but also to LTE used in conventional allocated frequency bands. That is, all the methods and configurations described in this embodiment can be applied not only to the LAA cell but also to LTE used in the conventional allocated frequency band.

Here, in the LAA cell, the period during which the LAA cell can transmit when the channel and / or the signal can be transmitted is defined based on the LBT. That period is also referred to as the maximum burst length, and the channels and / or signals transmitted during that period are also referred to as bursts. For example, the maximum burst length is 4 milliseconds (4 subframe lengths). Therefore, in each burst, the first subframe of the burst is the first subframe, and the last subframe of the burst is the second subframe. The partial subframe is also called a floating subframe. Further, the partial subframe may be a subframe including a symbol / subframe in which the channel and / or the signal is not transmitted (cannot be transmitted) described in the present embodiment.

Further, in a certain subframe, the subframe in which the area from the first OFDM symbol (subframe boundary) of the subframe to the last OFDM symbol (subframe boundary) of the subframe can be transmitted is a full subframe. Also called. A full subframe is a subframe other than a partial subframe. A full subframe is, in each burst, a subframe other than the first subframe of the burst or the last subframe of the burst. The full subframe may be a subframe that does not include the channels and / or symbols / subframes in which the signal is not transmitted (cannot be transmitted) as described in this embodiment. Further, the full subframe in the LAA cell may be a subframe having the same configuration and / or processing as the normal subframe in the normal cell.

FIG. 5 is a diagram showing an example of a communication procedure in a certain LAA cell. FIG. 5 shows 10 subframes shown in subframes # 0 to 9 and 14 symbols (OFDM symbols) of symbols # 0 to 13 in subframe # 3. Further, in this example, the LAA cell can transmit a signal of up to 4 milliseconds (corresponding to 4 subframes), and CCA is performed at symbol # 5 in subframe # 3. Further, it is assumed that the LAA cell identifies that the frequency is in the idle state in the CCA, and a signal can be transmitted from the symbol immediately after that. In FIG. 5, the LAA cell transmits a signal from symbol # 6 in subframe # 3 to a predetermined symbol in subframe # 6.

In FIG. 5, a symbol or subframe represented by a symbol / subframe in which a channel and / or signal is not transmitted (cannot be transmitted) indicates that the LAA does not transmit anything. Also, in FIG. 5, in the symbol or subframe represented by the symbol / subframe in which the channel and / or signal is transmitted (can be transmitted), the LAA has at least a PDSCH and a terminal-specific reference signal associated with the PDSCH. Indicates to send. Further, the PDSCH is mapped (scheduled) for each terminal in units of resource block pairs. Information about the mapping (scheduling) is notified through PDCCH or EPDCCH transmitted in each subframe. The mapping information for PDSCH in one subframe may be notified in the same subframe or may be notified in another subframe.

In FIG. 5, when the LAA cell transmits the PDSCH using the symbols # 6 to 13 in the subframe # 3, the terminal receiving the PDSCH maps the PDSCH to the symbols # 6 to 13 in the subframe # 3. You need to be aware that

In an example of the recognition method, information for recognizing a symbol to which a channel and / or a signal is transmitted is used in a predetermined subframe (for example, subframe # 3) of the LAA cell. For example, the information is any of the following, or a combination thereof.
(1) The information is information indicating a start symbol of a symbol to which a channel and / or a signal is transmitted in the predetermined subframe. The information indicating the start symbol is any of 0 to 13, and each value indicates a symbol number serving as a start symbol.
(2) The information is information indicating a start symbol of a symbol to which a channel and / or a signal is transmitted in the predetermined subframe. The information indicating the start symbol is index information obtained by indexing a predetermined value from a value of 0 to 13.
(3) The information is bitmap information indicating a symbol to which a channel and / or a signal is transmitted in the predetermined subframe. Bitmap information consists of 14 bits. In the bitmap information, if each bit is in one state (eg, 1), it indicates the symbol through which the channel and / or signal is transmitted, and if each bit is in the other state (eg, 0). Indicates a symbol for which no channel and / or signal is transmitted.
(5) The information is information indicating the last symbol of the symbol for which the channel and / or the signal is not transmitted, or information indicating the number of symbol symbols for which the channel and / or the signal is not transmitted in the predetermined subframe. For example, the last symbol is any of 0 to 13, and each value indicates the symbol number which is the last symbol. For example, the information indicating the number of symbols is any of 1 to 14, and each value indicates the number of symbols.
(6) The information is information indicating the last symbol of the symbol for which the channel and / or the signal is not transmitted, or information indicating the number of symbol symbols for which the channel and / or the signal is not transmitted in the predetermined subframe. For example, the last symbol is index information in which a predetermined value from 0 to 13 is indexed. For example, the information indicating the number of symbols is index information in which a predetermined value is indexed from a value of 1 to 14.

Further, as a method of notifying information for recognizing a symbol to which a channel and / or a signal is transmitted, for example, the following method is used.
(1) The information is notified by a parameter set (notified) for the LAA cell through RRC signaling or MAC signaling. When one serving cell is a LAA cell, in one subframe, the configured symbols do not transmit channels and / or signals, and the other symbols transmit channels and / or signals. For example, symbols for which no channel and / or signal is transmitted are set to be symbols # 0 and 1 in a subframe. Symbols for which no channel and / or signal is transmitted are set to be symbols # 2-13 in some subframes. Also, this setting may be different (or independent) depending on the channel and / or signal. For example, in a subframe, the terminal is set to map EPDCCH to symbols # 2-13 and PDSCH to symbols # 1-13. Further, for example, the PDSCH start symbol range (possible value) set for the LAA cell is different from the PDSCH start symbol range (1 to 4) set for the conventional secondary cell. Can be done. The range of PDSCH and / or EPDCCH start symbols set for the LAA cell is 0-13.
(2) The information is notified by PDCCH or EPDCCH transmitted from the LAA cell or a serving cell (assist cell, primary cell, or secondary cell) different from the LAA cell. The DCI carried (transmitted) by the PDCCH or EPDCCH contains that information.
(3) The information is notified by a channel or a signal for notifying the information. The channel or signal for notifying the information is transmitted only to the LAA cell. The channel or signal for notifying the information is transmitted from the LAA cell or a serving cell (assist cell, primary cell, or secondary cell) different from the LAA cell.
(4) The candidate for the information is set (notified) to the LAA cell through RRC signaling or MAC signaling. From the candidates for that information, it is selected based on the information contained in the DCI carried (transmitted) by the PDCCH or EPDCCH. For example, through RRC signaling or MAC signaling, information indicating four start symbols is set, and 2-bit information indicating one of them is notified by PDCCH or EPDCCH signaling.
(5) The information is notified by a channel or signal mapped to a predetermined resource element in a certain subframe. For example, the predetermined resource element is a plurality of resource elements in a predetermined symbol. For example, a given symbol is the last symbol in its subframe. The subframe to which the channel or signal for notifying the information is mapped may be all subframes in the LAA cell, or may be a predetermined subframe or a subframe set by RRC signaling. You may.
(6) The information is specified in advance. When a serving cell is a LAA cell, in some subframes a given symbol does not transmit a channel and / or signal, and another symbol transmits a channel and / or signal. For example, the symbols through which no channel and / or signal is transmitted are symbols # 0 and 1 in a subframe. Symbols for which no channel and / or signal is transmitted are symbols # 2-13 in a subframe. Also, this provision may vary (or be independent) by channel and / or signal. For example, in a subframe, the terminal assumes that EPDCCH is mapped to symbols # 2-13 and PDSCH is mapped to symbols # 1-13.

In another example of the recognition method, in a predetermined subframe (eg, subframe # 3) of the LAA cell, the terminal detects a channel and / or a symbol to which a signal is transmitted. Further, the terminal may be set with assist information for performing the detection. For example, the detection method uses the following method.
(1) The detection is performed based on a predetermined signal mapped to the predetermined subframe. The terminal detects the channel and / or the symbol on which the signal is transmitted based on whether a predefined or set signal has been detected in that predetermined subframe. When a predetermined signal or a preset signal is detected in a symbol of the predetermined subframe, the terminal transmits a channel and / or a signal of the symbol after the symbol in the predetermined subframe. Recognize as a symbol to be played. For example, the predefined or set signals are CRS, DMRS, and / or URS.
(2) The detection is performed based on a predetermined channel mapped to the predetermined subframe. The terminal detects a channel and / or a symbol to which a signal is transmitted based on whether a predetermined channel or a preset channel is detected in the predetermined subframe. When a predetermined channel or a preset channel is detected in a symbol having a predetermined subframe, the terminal transmits a channel and / or a signal to a symbol after the symbol in the predetermined subframe. Recognize as a symbol to be played. For example, the predefined or configured channel is EPDCCH. Specifically, the terminal performs EPDCCH monitoring (detection processing, blind detection) on the assumption that the EPDCCH is mapped to the symbols after a certain symbol in the predetermined subframe. Here, the terminal may blindly detect a start symbol that assumes that EPDCCH is mapped. Further, the start symbol or the candidate of the start symbol assuming that the EPDCCH is mapped may be defined in advance or may be set.

Further, in subframe # 3 of FIG. 5, the mapping method of PDCCH, EPDCCH and / or PDSCH to the resource element may be different from the mapping method in other subframes. For example, the following method can be used as the mapping method. The following mapping method (mapping order) can be applied to other signals such as a reference signal and a synchronization signal.
(1) In the mapping method, PDCCH, EPDCCH and / or PDSCH are mapped from the last symbol in the subframe. That is, the mapping of PDCCH, EPDCCH and / or PDSCH to the resource element (k, l) is an allocated physical resource block, and among the resource elements that can be mapped, the OFDM symbol having the largest OFDM symbol number l (that is, that is). , The last symbol in the slot). In addition, mapping is performed in order from the last slot (second slot) of the subframe. Also, in each OFDM symbol, those channels are mapped in order from the subcarrier with the smallest subcarrier number k.
(2) The mapping method is that the PDCCH, EPDCCH and / or PDSCH is mapped to the resource element in the symbol in which the channel and / or the signal is transmitted, skipping the symbol in which the channel and / or the signal is not transmitted. To. That is, in the mapping of PDCCH, EPDCCH and / or PDSCH, the resource elements of the symbols whose channels and / or signals are not transmitted are rate matched.
(3) The mapping method is that PDCCH, EPDCCH and / or PDSCH maps to the resource element in the symbol to which the channel and / or signal is transmitted without skipping the symbol to which the channel and / or signal is not transmitted. Will be done. In other words, PDCCH, EPDCCH and / or PDSCH are mapped without distinguishing between symbols that transmit channels and / or signals from symbols that do not transmit channels and / or signals, but channels and / or signals. Channels that are mapped to symbols that are not transmitted are not transmitted, channels and / or channels that are mapped to symbols that are signaled are transmitted. That is, in the mapping of PDCCH, EPDCCH and / or PDSCH, the resource element of the symbol whose channel and / or signal is not transmitted is punctured.

FIG. 6 is a diagram showing an example of a communication procedure in a certain LAA cell. Hereinafter, differences from the contents described with reference to FIG. 5 will be described. In this example, CCA is performed on symbol # 5 in subframe # 3. Further, it is assumed that the LAA cell identifies that the frequency is in the idle state in the CCA, and a signal can be transmitted from the symbol immediately after that. The LAA cell transmits a signal from symbol # 5 in subframe # 3 to a predetermined symbol in subframe # 6.

In an example of FIG. 6, symbols # 6 and 7 in subframe # 3 are symbols to which a reservation signal is transmitted. The reserved signal is transmitted immediately after the symbol performing the CCA (ie, symbol # 5) and immediately before the channel and / or the symbol to which the signal is transmitted (ie, symbol # 6). The effect of this reservation signal is as follows. As described in FIG. 5, the LAA cell does not depend on the number of candidates for the CCA, even if the candidates for the channel and / or the symbol to which the signal is transmitted are predetermined or set. It can be done flexibly.

The reserved signal may or may not be received (recognized) by the terminal receiving the channel and / or signal transmitted from the LAA cell. That is, if the channel and / or signal cannot be transmitted after the CCA is performed, the reserved signal is transmitted so that the LAA cell that has performed the CCA secures (reserves) its frequency.

The symbol on which the reserved signal is transmitted may be mapped to a channel and / or signal different from the channel and / or signal transmitted by the symbol on which the signal is transmitted. That is, the channel and / or signal mapped to the symbol to which the reserved signal is transmitted is recognized (received) by the terminal. For example, the terminal identifies the symbol on which the channel and / or signal is transmitted based on the channel and / or signal that is mapped to the symbol on which the reserved signal is transmitted. Also, for example, the terminal synchronizes (identifies) with its LAA cell using the channel and / or signal mapped to the symbol to which the reserved signal is transmitted.

The reserved signal in the present embodiment is also referred to as an initial signal. The initial signal is the signal transmitted at the beginning of the burst and can be distinguished from the PDSCH, EPDCCH, PDCCH and / or reference signal within the burst. The initial signal can also include control information about the burst, control information about channels and / or signals within the burst, or control information about the cell transmitting the burst.

FIG. 7 is a diagram showing an example of a communication procedure in a certain LAA cell. Hereinafter, differences from the contents described with reference to FIG. 5 will be described. In this example, CCA is performed at symbol # 5 in subframe # 3, as in the example of FIG. Further, it is assumed that the LAA cell identifies that the frequency is in the idle state in the CCA, and a signal can be transmitted from the symbol immediately after that. In FIG. 7, the LAA cell transmits a signal from symbol # 6 in subframe # 3 to symbol # 5 in subframe # 7 after 4 milliseconds.

In one example of FIG. 7, the LAA cell transmits a reservation signal from the symbol immediately after the symbol performing CCA to the last symbol in the subframe including the symbol performing CCA. The LAA cell also transmits channels and / or signals from the next subframe of the subframe containing the symbol performing the CCA. Further, the reservation signal in FIG. 7 includes the reservation signal described in FIG.

For example, in FIG. 7, the terminal can be assumed to transmit channels and / or signals in subframes # 4 and beyond. This assumes that the terminal transmits the channel and / or signal from the first symbol of the subframe. Therefore, the base station including the LAA cell can use the same method as before for transmitting the channel and / or the signal to the terminal and notifying the control information for the channel and / or the signal. ..

Also, in FIG. 7, the LAA cell can transmit channels and / or signals from the first symbol to symbol # 5 in subframe # 7. For example, the LAA cell can transmit to the terminal a PDSCH and / or EPDCCH mapped to resources from a given symbol to symbol # 5 in subframe # 7. In addition, the LAA cell can transmit the PDCCH mapped to the resources from the first symbol in the subframe # 7 to the predetermined symbol to the terminal. For example, a given symbol is information transmitted by PCFICH and is determined based on information about the number of OFDM symbols used for PDCCH transmission. Further, for example, a predetermined symbol is control information set by RRC signaling and is determined based on information indicating an OFDM start symbol for EPDCCH, PDSCH scheduled by PDCCH, and PDSCH scheduled by EPDCCH. ..

Also, in FIG. 7, the LAA cell may notify or set the terminal in subframe # 7 of the last symbol on which the channel and / or signal is transmitted. As the information for the terminal to recognize the last symbol in a certain subframe of the LAA cell and the method of notifying the information, the method described in the example of FIG. 5 can be used. The method described in one example of FIG. 5 is information for recognizing a channel and / or a symbol to which a signal is transmitted in FIG. 5 and a method of notifying the information. For example, the LAA cell includes information about its last symbol in the DCI notified by PDCCH or EPDCCH transmitted in subframe # 7. This allows the LAA cell to efficiently use resources when channels and / or signals can be transmitted to symbols in the middle of the subframe, as in subframe # 7 in FIG. Also, for example, the LAA cell includes information about its last symbol in the information set by RRC signaling or MAC signaling.

Further, in FIG. 7, a method in which the transmission method in the subframe # 3 and the transmission method in the subframe # 7 are used in combination has been described, but the present invention is not limited thereto. The transmission method in subframe # 3 and the transmission method in subframe # 7 may be used independently of each other. In addition, some or all of the methods described in FIGS. 5 to 7 may be used in combination.

Further, in subframe # 7 of FIG. 7, the mapping of PDCCH, EPDCCH and / or PDSCH to the resource element may be different from the mapping in other subframes.

Further, in the LAA cell, subframes capable of transmitting channels and / or signals to all OFDM symbols in one subframe (that is, subframes # 4 to 6 in FIGS. 5 to 7) are a part of one subframe. Recognized, set, or notified as a different subframe from the subframes (ie, subframes # 3 in FIGS. 5-7 and # 7 in FIGS. 7) that cannot transmit channels and / or signals to the OFDM symbol of You may. For example, a subframe capable of transmitting channels and / or signals to all OFDM symbols in one subframe is equivalent to a subframe in a conventional serving cell.

In the present embodiment, a subframe in which a channel and / or a signal cannot be transmitted to all OFDM symbols in one subframe is also referred to as a first LAA subframe. Subframes that cannot transmit channels and / or signals to some OFDM symbols in one subframe are also referred to as second LAA subframes. A subframe capable of transmitting channels and / or signals to all OFDM symbols in one subframe is also referred to as a third LAA subframe. The second LAA subframe is also referred to as a partial subframe, and the third LAA subframe is also referred to as a full subframe. The second LAA subframe includes a first subframe, a second subframe, and / or a third subframe.

Further, as a method for the terminal to recognize the first LAA subframe, the second LAA subframe, and the third LAA subframe, the method described in the present embodiment can be used. For example, the method for recognizing them uses the information for recognizing the symbol to which the channel and / or the signal is transmitted and the notification method thereof.

Further, the method for the terminal to recognize the first LAA subframe, the second LAA subframe, and the third LAA subframe may be explicitly notified or set by PDCCH or RRC signaling. ..

Further, the method for the terminal to recognize the first LAA subframe, the second LAA subframe, and the third LAA subframe is based on the information (parameter) notified or set by the signaling of PDCCH or RRC. May be implicitly notified or set. For example, the terminal recognizes the first LAA subframe, the second LAA subframe, and the third LAA subframe based on the information about the CRS mapping.

Further, when the terminal recognizes that a certain subframe is the second LAA subframe, it recognizes that a predetermined number of subframes after the next subframe of the certain subframe are the third LAA subframe. .. Further, the terminal recognizes that the subframe after the last subframe recognized as the third LAA subframe is the second LAA subframe until the terminal recognizes that the subframe is the second LAA subframe. Recognize that. Further, the predetermined number (that is, the number of subframes recognized as the third LAA subframe) may be predetermined. The predetermined number may be set in the LAA cell. The predetermined number may be signaled by a channel and / or signal mapped to a second LAA subframe.

Further, in the second LAA subframe and the third LAA subframe, the start symbols of PDSCH and / or EPDCCH are independently defined or set, respectively.

Further, in FIGS. 5 to 7, it is shown that the CCA is performed in one subframe, but the time (duration) for performing the CCA is not limited to this. The time for performing CCA may vary for each LAA cell, each CCA timing, and each CCA execution. For example, CCA is performed at a time based on a predetermined time slot (time interval, time domain). The predetermined time slot may be defined or set by the time obtained by dividing one subframe into a predetermined number. The predetermined time slot may be defined or set by a predetermined number of subframes.

Further, in the present embodiment, the size of the field in the time domain, such as the time for performing CCA (time slot) and the time for transmitting (transmitting) a channel and / or signal in a certain subframe, is a predetermined time unit. Can be expressed using. For example, the size of a field in the time domain is expressed as some time unit Ts. Ts is 1 / (15000 * 2048) seconds. For example, the time for one subframe is 30720 * Ts (1 millisecond).

Further, as in subframe # 3 in FIGS. 5 to 7, whether or not the channel and / or signal (including the reserved signal) can be transmitted from the symbol in the middle of the subframe in which the LAA cell is present depends on the terminal or the LAA cell. May be set for. For example, the terminal is set by RRC signaling in the settings related to the LAA cell to indicate whether such transmission is possible. The terminal switches the processing related to reception (monitoring, recognition, decoding) in the LAA cell based on the information.

Further, the subframe that can be transmitted from the symbol in the middle (including the subframe that can be transmitted to the symbol in the middle) may be all the subframes in the LAA cell. Further, the subframe that can be transmitted from the symbol in the middle may be a subframe predetermined or a set subframe for the LAA cell.

In addition, the subframes that can be transmitted from the symbols in the middle (including the subframes that can be transmitted to the symbols in the middle) are set, notified, or determined based on the TDD uplink / downlink settings (UL / DL settings). Can be done. For example, such a subframe is a subframe notified (designated) as a special subframe in the UL / DL settings. The special subframe in the LAA cell is a subframe containing at least one of three fields of DwPTS (Downlink Pilot Time Slot), GP (Guard Period) and UpPTS (Uplink Pilot Time Slot). Settings for special subframes in LAA cells may be set or signaled by RRC signaling, PDCCH or EPDCCH signaling. This setting sets the length of time for at least one of DwPTS, GP and UpPTS. Further, this setting is index information indicating a candidate for a predetermined time length. Further, this setting can use the same time length as DwPTS, GP and UpPTS used in the special subframe setting set in the conventional TDD cell. That is, the length of time that can be transmitted in a certain subframe is determined based on one of DwPTS, GP, and UpPTS.

Further, in the present embodiment, the reserved signal can be a signal that can be received by a LAA cell different from the LAA cell transmitting the reserved signal. For example, a LAA cell different from the LAA cell transmitting the reservation signal is an LAA cell (adjacent LAA cell) adjacent to the LAA cell transmitting the reservation signal. For example, the reservation signal includes information regarding the transmission status (usage status) of a predetermined subframe and / or symbol in the LAA cell. When a LAA cell different from the LAA cell transmitting a reservation signal receives the reservation signal, the LAA cell receiving the reservation signal of a predetermined subframe and / or symbol based on the reservation signal. Recognize the transmission status and perform scheduling according to the status.

Further, the LAA cell that has received the reserved signal may perform LBT before transmitting the channel and / or the signal. The LBT is performed based on the received reservation signal. For example, in the LBT, scheduling including resource allocation and selection of MCS is performed in consideration of the channel and / or signal transmitted (assumed to be transmitted) by the LAA cell that transmitted the reserved signal.

Further, when the LAA cell that has received the reserved signal schedules transmission of a channel and / or signal based on the reserved signal, one or more LAA cells including the LAA cell that has transmitted the reserved signal are scheduled by a predetermined method. Information about the scheduling can be notified to the LAA cell. For example, the predetermined method is a method of transmitting a predetermined channel and / or signal including a reserved signal. Further, for example, the predetermined method is a method of notifying through a backhaul such as an X2 interface.

Further, in carrier aggregation and / or dual connectivity, the conventional terminal can set up to five serving cells, but the terminal in the present embodiment can expand the maximum number of serving cells that can be set. That is, the terminal in this embodiment can set more than five serving cells. For example, the terminal in this embodiment can set up to 16 or 32 serving cells. For example, more than five serving cells set on the terminal in this embodiment include LAA cells. Further, all of the five or more serving cells set in the terminal in the present embodiment may be LAA cells.

Further, when more than five serving cells can be set, the settings related to some serving cells may be different from the settings of the conventional serving cell (that is, the conventional secondary cell). For example, regarding the setting, the following is different. The settings described below may be used in combination.
(1) Up to 5 conventional serving cells are set in the terminal, and up to 11 or 27 serving cells different from the conventional ones are set. That is, in the terminal, in addition to the conventional primary cell, up to four conventional secondary cells are set, and up to 11 or 27 secondary cells different from the conventional one are set.
(2) The setting related to the serving cell (secondary cell) different from the conventional one includes the setting related to the LAA cell. For example, in the terminal, in addition to the conventional primary cell, up to four secondary cells that do not include the setting related to the LAA cell are set, and up to 11 or 27 secondary cells different from the conventional one are set.

Further, when more than five serving cells can be set, the base station (including the LAA cell) and / or the terminal can perform processing or assumption different from the case of setting up to five serving cells. For example, with respect to its processing or assumptions: The processes or assumptions described below may be used in combination.
(1) The terminal assumes that PDCCH, EPDCCH and / or PDSCH are simultaneously transmitted (received) from a maximum of five serving cells even when more than five serving cells are set. Thereby, the terminal can use the same method as before for receiving the PDCCH, EPDCCH and / or PDSCH, and transmitting HARQ-ACK to the PDSCH.
(2) When five or more serving cells are set in the terminal, a combination (group) of cells for bundling HARQ-ACK with respect to PDSCH is set in those serving cells. For example, all serving cells, all secondary cells, all LAA cells, or all non-conventional secondary cells each contain information (settings) regarding the bundling of HARQ-ACK between serving cells. For example, the information regarding the bundling of HARQ-ACK between serving cells is an identifier (index, ID) that performs the bundling. For example, HARQ-ACK is bundled across cells whose bundling identifiers are the same. The bundling is performed by a logical product operation on the target HARQ-ACK. Further, the maximum number of identifiers that perform the bundling can be 5. Further, the maximum number of identifiers that perform the bundling can be 5 including the number of cells that do not perform the bundling. That is, the maximum number of groups that perform bundling beyond the serving cell can be five. Thereby, the terminal can use the same method as before for receiving the PDCCH, EPDCCH and / or PDSCH, and transmitting HARQ-ACK to the PDSCH.
(3) When five or more serving cells are set in the terminal, a combination (group) of cells for multiplexing HARQ-ACK with respect to PDSCH is set in those serving cells. When a combination (group) of cells for multiplexing HARQ-ACK with respect to PDSCH is set, the multiplexed HARQ-ACK is transmitted by PUCCH or PUSCH based on the group. In each group, the maximum number of serving cells to be multiplexed is specified or set. The maximum number is defined or set based on the maximum number of serving cells set in the terminal. For example, the maximum number is the same as the maximum number of serving cells set in the terminal, or half of the maximum number of serving cells set in the terminal. Further, the maximum number of PUCCHs transmitted at the same time is defined or set based on the maximum number of serving cells to be multiplexed in each group and the maximum number of serving cells set in the terminal.

In other words, the number of the first serving cells (that is, the primary cell and / or the secondary cell) to be set is a predetermined number (ie, 5) or less, and the first serving cell and the second serving cell to be set (that is, the second serving cell). That is, the total number of LAA cells) exceeds the predetermined number.

Next, terminal capabilities related to LAA will be described. Based on the instruction from the base station, the terminal notifies (transmits) information (terminal capability) regarding the capability (capability) of the terminal to the base station by RRC signaling. The terminal capability for a certain function (feature) is notified (transmitted) when the function (feature) is supported, and is not notified (sent) when the function (feature) is not supported. Further, the terminal capability for a certain function (feature) may be information indicating whether or not the test and / or implementation of the function (feature) has been completed. For example, the terminal capabilities in this embodiment are as follows. The terminal capabilities described below may be used in combination.
(1) The terminal capability related to the support of the LAA cell and the terminal capability related to the support of the setting of more than 5 serving cells are defined independently. For example, a terminal that supports LAA cells supports the setting of more than five serving cells. That is, a terminal that does not support the setting of more than 5 serving cells does not support LAA cells. In that case, the terminal supporting the setting of more than 5 serving cells may or may not support the LAA cell.
(2) The terminal capability related to the support of the LAA cell and the terminal capability related to the support of the setting of more than 5 serving cells are defined independently. For example, a terminal that supports the setting of more than five serving cells supports LAA cells. That is, a terminal that does not support LAA cells does not support the setting of more than five serving cells. In that case, the terminal supporting the LAA cell may or may not support the setting of more than five serving cells.
(3) The terminal capability related to the downlink in the LAA cell and the terminal capability related to the uplink in the LAA cell are defined independently. For example, a terminal that supports an uplink in a LAA cell supports a downlink in the LAA cell. That is, a terminal that does not support the downlink in the LAA cell does not support the uplink in the LAA cell. In that case, the terminal that supports the downlink in the LAA cell may or may not support the uplink in the LAA cell.
(4) Terminal capabilities relating to LAA cell support include support for transmission modes that are set only for LAA cells.
(5) The terminal capability related to the downlink in the setting of more than 5 serving cells and the terminal capability related to the uplink in the setting of more than 5 serving cells are defined independently. For example, a terminal that supports uplinks in more than five serving cell settings supports downlinks in more than five serving cell settings. That is, a terminal that does not support downlink in the setting of more than 5 serving cells does not support the uplink in the setting of more than 5 serving cells. In that case, the terminal that supports the downlink in the setting of more than 5 serving cells may or may not support the uplink in the setting of more than 5 serving cells.
(6) Among the terminal capabilities in the setting of more than 5 serving cells, the terminal capabilities that support the setting of up to 16 downlink serving cells (component carriers) and the terminal capabilities that support the setting of up to 32 downlink serving cells are. , Each is defined independently. In addition, a terminal that supports the setting of up to 16 downlink serving cells supports the setting of at least one uplink serving cell. A terminal that supports the configuration of up to 32 downlink serving cells supports the configuration of at least two uplink serving cells. That is, a terminal that supports the setting of up to 16 downlink serving cells does not have to support the setting of two or more uplink serving cells.
(7) The terminal capability related to the support of the LAA cell is notified based on the frequency (band) used in the LAA cell. For example, in the notification of frequencies or frequency combinations supported by a terminal, if the notified frequency or combination of frequencies includes at least one frequency used in the LAA cell, the terminal implicitly implies that it supports the LAA cell. Notice. That is, if the frequency or frequency combination notified does not include any frequency used in the LAA cell, the terminal implicitly notifies that it does not support the LAA cell.

Next, the terminal capabilities related to the second EPDCCH will be described. In an example of terminal capabilities in this embodiment, the terminal capability field associated with the second EPDCCH defines whether the terminal can receive DCI in the USS and / or CSS of the second EPDCCH. That is, if the terminal can receive DCI in the USS and / or CSS of the second EPDCCH, it notifies that the terminal is supported in the field of terminal capabilities associated with the second EPDCCH. Also, if the terminal is unable to receive DCI in the USS and / or CSS of the second EPDCCH, the terminal will not notify the terminal capability field associated with the second EPDCCH.

Also, if the terminal is capable of receiving DCI in the USS and / or CSS of the second EPDCCH, the terminal is capable of receiving DCI in the USS of the first EPDCCH. That is, when notifying that the terminal is supported in the terminal capability field related to the second EPDCCH (Supported), it is supported in the terminal capability field related to the first EPDCCH (Supported). Notify. Also, if the terminal notifies that it is supported in the field of terminal capabilities associated with the second EPDCCH, it indicates that the terminal is capable of receiving DCI in the USS of the first EPDCCH. You may do so.

Also, if the terminal can receive DCI in the USS and / or CSS of the second EPDCCH, the terminal also has the ability for LAA (including, for example, those described above). That is, when the terminal notifies that it is supported in the terminal capability field related to the second EPDCCH (Supported), it notifies that it is supported in the terminal capability field related to LAA (Supported). .. Also, if the terminal notifies that it is supported in the field of terminal capabilities associated with the second EPDCCH, it may indicate that the terminal also has LAA capabilities.

Further, in the present embodiment, the case where the LAA cell transmits the PDCCH or EPDCCH notifying the DCI for the PDSCH transmitted in the LAA cell (that is, in the case of self-scheduling) has been described, but the present invention is limited to this. It is not something that is done. For example, the present embodiment also describes a case where a serving cell different from the LAA cell transmits a PDCCH or EPDCCH notifying the DCI for the PDSCH transmitted in the LAA cell (that is, in the case of cross-carrier scheduling). The method used is applicable.

Further, in the present embodiment, the information for recognizing the symbol to which the channel and / or the signal is transmitted may be based on the symbol to which the channel and / or the signal is not transmitted. For example, that information is information that indicates the last symbol of a symbol for which a channel and / or signal is not transmitted. Also, the information for recognizing the channel and / or the symbol to which the signal is transmitted may be determined based on other information or parameters.

Further, in the present embodiment, the symbol to which the channel and / or the signal is transmitted may be set (notified, specified) independently of the channel and / or the signal. That is, the information for recognizing the symbol to which the channel and / or the signal is transmitted and the notification method thereof can be set (notified, specified) independently for the channel and / or the signal. For example, the information for recognizing the symbol to which the channel and / or the signal is transmitted and the notification method thereof can be set (notified, specified) independently in PDSCH and EPDCCH, respectively.

Further, in the present embodiment, the symbol / subframe in which the channel and / or the signal is not transmitted (cannot be transmitted) is a symbol / subframe in which the channel and / or the signal is not assumed to be transmitted (can be transmitted) from the viewpoint of the terminal. May be. That is, the terminal can be considered that the LAA cell is not transmitting a channel and / or signal at that symbol / subframe.

Further, in the present embodiment, the symbol / subframe to which the channel and / or signal is transmitted (can be transmitted) is a symbol / subframe that assumes that the channel and / or signal may be transmitted from the viewpoint of the terminal. May be. That is, the terminal can consider that the LAA cell may or may not be transmitting channels and / or signals in its symbols / subframes.

Further, in the present embodiment, the symbol / subframe in which the channel and / or signal is transmitted (can be transmitted) is a symbol / subframe in which it is assumed that the channel and / or signal is always transmitted from the viewpoint of the terminal. May be good. That is, the terminal can consider that the LAA cell is always transmitting channels and / or signals in its symbols / subframes.

Further, in the present embodiment, the LAA cell may be a serving cell using a predetermined frequency band.

Next, an extended physical downlink control channel (EPDCCH: Enhanced Physical Downlink Control Channel) will be described. The EPDCCH is transmitted and received using a resource element (RE: Resource Element) like other physical channels such as PDSCH. Each element (element corresponding to one subcarrier and one OFDM symbol) of the resource grid for the antenna port P (the transmitted signal is described by a grid of subcarriers and OFDM symbols for each slot) is RE. Is uniquely identified in one slot by a pair of indexes, k (starting from 0 and ascending in the frequency axis) and l (starting from 0 and ascending in the time axis). To.

EPDCCHs are normal subframes in normal cells, partial subframes in LAA cells, and / or full subframes in LAA cells, which may differ in configuration and / or processing. For example, in the partial subframe, an EPDCCH composed of fewer OFDM symbols than the EPDCCH used in the normal subframe and / or the full subframe is used. In this embodiment, the EPDCCH used in the normal subframe is also referred to as the first EPDCCH, and the EPDCCH used in the partial subframe is also referred to as the second EPDCCH. The first EPDCCH and / or the second EPDCCH may be used in the full subframe.

FIG. 8 shows an example of the EREG configuration in one RB pair. EREG (Enhanced RE Group) is used to define the mapping of EPDCCH to RE. There are 16 EREGs numbered from 0 to 15 for each resource block pair. Excludes REs that carry DMRS for antenna ports 107, 108, 109 and 110 for normal CP (Cyclopic Prefix) and DMRS for antenna ports 107 and 108 for extended CP within one PRB pair. All REs are cyclically numbered from 0 to 15 in ascending order of frequency first and time later. In FIG. 8, the shaded resource elements are used to carry the DMRS. All the numbered REs in the PRB pair constitute the numbered EREG of i. Here, CP is a signal added before the effective symbol section of the OFDM symbol (SC-FDMA symbol in the case of uplink) in the downlink, and is a part (usually the last part) in the effective symbol section. Is the copied signal. The CP length includes a normal CP having a normal length (for example, 160 samples or 144 samples for a valid symbol length of 2048 samples) and a longer CP length (for example, 512 samples or 1024 samples for a valid symbol length of 2048 samples). Sample) There are two types of extended CP.

Here, the configuration of EREG can be the same regardless of the first EPDCCH or the second EPDCCH. That is, the EREG in the first EPDCCH or the second EPDCCH is for each resource block pair with respect to the extended CP for antenna ports 107, 108, 109 and 110 with respect to the normal CP (Cyclic Prefix). Specified for all REs except those carrying DMRS for antenna ports 107 and 108. As a result, even if the DMRS configuration is different, the RE for configuring the EREG is different, but the definition for configuring the EREG is the same.

As shown in FIG. 8, one RB pair is composed of two RBs. Each RB is composed of resource elements represented by 7 OFDM symbols in the time direction and 12 subcarriers in the frequency direction. In FIG. 8, DMRS is mapped to shaded resource elements. Further, each DMRS is composed of two-chip orthogonal codes, and up to two DMRSs can be code-division multiple access. The DMRSs of antenna ports 107 and 108 are OFDM symbol numbers 5 and 6 in their respective slots and are mapped to REs which are subcarrier numbers 0, 5 and 10. The DMRSs of antenna ports 109 and 110 are OFDM symbol numbers 5 and 6 in their respective slots and are mapped to REs which are subcarrier numbers 1, 6 and 11. Here, as the DMRS associated with the first EPDCCH, the DMRS described with reference to FIG. 8 can be used.

As an example of the DMRS associated with the second EPDCCH, the DMRS described in FIG. 8 can be used. That is, the DMRS associated with the second EPDCCH can use the same configuration as the DMRS associated with the first EPDCCH, but if the OFDM symbol that the second EPDCCH cannot transmit contains DMRS, the DMRS is Not sent. For example, in the partial subframes of OFDM symbols # 0-6 in slot 1, the DMRS associated with the second EPDCCH is mapped only to OFDM symbols # 5 and 6 in slot 1 and OFDM symbols # 5 and 6 in slot 0. Not mapped to only. If any of the two OFDM symbols to which the orthogonal codes of the two chips are mapped cannot be transmitted, it is assumed that the DMRS is not transmitted.

Another example of DMRS associated with a second EPDCCH depends on the OFDM symbol used to transmit the second EPDCCH. Specifically, the RE to which the DMRS associated with the second EPDCCH is mapped is defined according to the configuration of the OFDM symbol used for transmitting the second EPDCCH. A predetermined number of patterns can be predetermined in the configuration of the OFDM symbol used for the transmission of the second EPDCCH. That is, as for the configuration of the DMRS associated with the second EPDCCH, a predetermined number of patterns can be similarly defined in advance.

FIG. 9 is a diagram showing an example of the configuration of DMRS associated with the second EPDCCH used for the first subframe. In FIG. 9, shaded REs indicate REs to which the DMRS associated with the second EPDCCH is mapped. Dot-shaded REs indicate REs (OFDM symbols) that are not used to transmit the second EPDCCH. That is, in FIG. 9A, the OFDM symbol # 0 in slot 0 is the start symbol of the second EPDCCH, and in FIG. 9B, the OFDM symbol # 3 in slot 0 is the start symbol of the second EPDCCH. In FIG. 9C, the OFDM symbol # 0 in slot 1 is the start symbol of the second EPDCCH, and in FIG. 9D, the OFDM symbol # 0 in slot 1 is the second EPDCCH. In FIG. 9 (e), the OFDM symbol # 3 in slot 1 is the start symbol of the second EPDCCH. As shown in FIG. 9, the configuration of the DMRS associated with the second EPDCCH can be defined according to the start symbol of the second EPDCCH.

FIG. 10 is a diagram showing an example of the configuration of DMRS associated with the second EPDCCH used for the second subframe. In FIG. 10, shaded REs indicate REs to which the DMRS associated with the second EPDCCH is mapped. Dot-shaded REs indicate REs (OFDM symbols) that are not used to transmit the second EPDCCH. That is, in FIG. 10A, the OFDM symbol # 6 in slot 1 is the end symbol of the second EPDCCH, and in FIG. 10B, the OFDM symbol # 3 in slot 1 is the end of the second EPDCCH. In FIG. 10 (c), the OFDM symbol # 1 in slot 1 is the end symbol of the second EPDCCH, and in FIG. 10 (d), the OFDM symbol # 6 in slot 0 is the second EPDCCH. In FIG. 10 (e), the OFDM symbol # 4 in slot 0 is the end symbol of the second EPDCCH. As shown in FIG. 10, the configuration of the DMRS associated with the second EPDCCH can be defined according to the end symbol of the second EPDCCH. Also, the configuration of the DMRS associated with the second EPDCCH used in the second subframe can be the same as the configuration of the DMRS used in the DwPTS.

The EPDCCH carries the scheduling assignment. One EPDCCH is transmitted using an aggregate (aggregation) of one or several consecutive ECCEs (Enhanced Control Channel Elements). Here, each ECCE is composed of a plurality of EREGs. The number of ECCEs used for an EPDCCH depends on the format of that EPDCCH and the number of EREGs per ECCE. Both local and decentralized transmissions are supported. One EPDCCH can use either local or distributed transmission with different mappings of ECCE to EREG and PRB pairs.

Further, in the first EPDCCH, either local transmission or distributed transmission can be set for each EPDCCH set through RRC signaling. The second EPDCCH can predefine either local or distributed transmission for all EPDCCH sets. For example, the second EPDCCH can predefine decentralized transmission for all EPDCCH sets.

The terminal device monitors a plurality of EPDCCHs as described later. The installation of one or two PRB pairs in which the terminal device monitors EPDCCH transmission can be configured. _{All EPDCCH candidates in the EPDCCH set X m} are used only for local transmission or only for distributed transmission, as set by the upper layer. In the EPDCCH set X _m of the subframe i, the ECCEs available for transmission of the EPDCCH are numbered from 0 to N _{ECCE, m, i} -1. Here, N _{ECCE, m, and i} are the number of ECCEs available for transmitting EPDCCH in the EPDCCH set X _{m of the subframe i.} In the case of local mapping, the ECCE of number n corresponds to the EREG numbered (n mod N ^RB _ECCE ) + jN ^RB _ECCE ^{in the PRB whose index is floor (n / N RB} _{ECCE) and is distributed.} for mapping, corresponding to the index is ^{_{(n + j max (1,}} n Xm RB / n ECCE EREG)) mod n Xm RB is a ^floor in ^{_{PRB (n / n Xm RB)}} + jN RB ECCE number is swung EREG To do. Here, j = 0, 1, ..., N ^ECCE _EREG -1, and N ^ECCE _EREG is the number of EREGs per ECCE. ^Further, _{N RB ECCE} is equal to ^{16 /} _{N ECCE EREG,} the number of ECCE per PRB pair. Further, floor, mod, and max are a floor function, a remainder function (mod function), and a maximum value function (max function), respectively. Here, the PRB pairs configuring the EPDCCH set _{X m} is assumed to be dumped or numbers in ascending order from 0 to ^N _Xm RB -1.

In the first ^EPDCCH, _{N ECCE EREG} is determined based on the type of the CP and the subframe. More specifically, in the case of a normal CP and a normal subframe (normal downlink subframe), or in the case of a normal CP and a special subframe with a special subframe setting of 3, 4 or 8, ^NECCE _{The EREG} is 4. In the case of a normal CP and a special subframe with a special subframe setting of 1, 2, 6, 7 or 9 (that is, a special subframe consisting of 6 or more and 10 or less OFDM symbols of DwPTS), the extended CP And in the case of normal subframes, or special subframes with extended CP and special subframe settings of 1, 2, 3, 5 or 6 (that is, specials consisting of OFDM symbols with 6 or more and 10 or less DwPTS) for ^sub-frame), _{N ECCE EREG} is 8. The details of the special subframe setting will be described later.

An example of ^N _{ECCE EREG} in the second EPDCCH ^is, _{N ECCE EREG} is a predefined value. For example, ^N _{ECCE EREG} in the second EPDCCH is normal CP and special subframe configuration in the first EPDCCH is the same as in the special subframe of 1,2,6,7 or 9, 8. Further, for example, ^N _{ECCE EREG} in the second EPDCCH is the same as the number of EREG consisting of one resource block pair, it is 16.

Another example of ^N _{ECCE EREG} in the second EPDCCH ^is _{N ECCE EREG} is detected (envisioned are monitored) determined depending on the _{n EPDCCH} (described later) in the second EPDCCH. Specifically, when _{n EPDCCH} in the second EPDCCH is equal to or more than a predetermined ^number, _{N ECCE EREG} is 4 (or 8), when its smaller than a predetermined ^number, _{N ECCE EREG} is 8 (or 16) is there. The predetermined number may be predetermined, or may be set cell-specific or terminal-specific through RRC signaling. For example, the predetermined number is the same as the predetermined number used in the first EPDCCH, which is 104. Further, for example, the predetermined number may be different from the predetermined number used in the first EPDCCH.

Further, a _{plurality of predetermined numbers for n EPDCCH} may be specified or set. Specifically, when the case _{n EPDCCH} in the second EPDCCH is not less than the first predetermined ^number, _{N ECCE EREG} is 4, smaller than the first predetermined number is the second predetermined number or more, N ^ECCE _EREG is 8, when the second less than a predetermined ^number, _{N ECCE EREG} is 16. For example, the first predetermined number is the same as the predetermined number used in the first EPDCCH, which is 104. The second predetermined number is a value smaller than the first predetermined number.

Another example of ^N _{ECCE EREG} in the second EPDCCH ^is _{N ECCE EREG} is detected (envisioned are monitored) determined depending on the number of OFDM symbols in the second EPDCCH. Specifically, if the number of OFDM symbols in the second EPDCCH is equal to or more than a predetermined ^number, _{N ECCE EREG} is 4 (or 8), when its smaller than a predetermined ^number, _{N ECCE EREG} is 8 (or 16 ). The predetermined number may be predetermined, or may be set cell-specific or terminal-specific through RRC signaling.

Further, a plurality of predetermined numbers may be specified or set with respect to the number of OFDM symbols. Specifically, if the number of OFDM symbols in the second EPDCCH is not less than the first predetermined ^number, _{N ECCE EREG} is 4, and the second predetermined number or more if less than the first predetermined number , N ^ECCE _EREG is 8, and if it is smaller than the second predetermined number, N ^ECCE _EREG is 16. For example, the second predetermined number is a value smaller than the first predetermined number.

Another example of ^N _{ECCE EREG} in the second EPDCCH, like the first EPDCCH, but determined based on the type of the CP and the ^sub-frame, _{N ECCE EREG} is 2 times the value for the first EPDCCH .. More specifically, in the case of a normal CP and a normal subframe (normal downlink subframe), or in the case of a normal CP and a special subframe with a special subframe setting of 3, 4 or 8, ^NECCE _{The EREG} is 8. In the case of a normal CP and a special subframe with a special subframe setting of 1, 2, 6, 7 or 9 (that is, a special subframe consisting of 6 or more and 10 or less OFDM symbols of DwPTS), the extended CP And in the case of normal subframes, or special subframes with extended CP and special subframe settings of 1, 2, 3, 5 or 6 (that is, specials consisting of OFDM symbols with 6 or more and 10 or less DwPTS) for ^sub-frame), _{N ECCE EREG} is 16.

The correspondence between the EPDCCH format and the number of ECCEs (aggregation level) per EPDCCH can be specified. Further, the correspondence can be defined differently for the first EPDCCH and the second EPDCCH.

In the first EPDCCH, the correspondence between the EPDCCH format and the number of ECCEs (aggregation level) per EPDCCH can specify a plurality of cases A and B. Case A is used when the conditions corresponding to Case 1 described later are satisfied, and Case B is used in other cases. Aggregation levels in Case A are 2, 4, 8 and 16 for local transmission and 2, 4, 8, 16 and 32 for distributed transmission. Aggregation levels in Case B are 1, 2, 4 and 8 for local transmission and 1, 2, 4, 8 and 16 for distributed transmission. That is, the aggregation level in case A is higher than the aggregation level in case B. As a result, even when the number of REs used for each of the EREGs in the EPDCCH is small, a predetermined reception characteristic for the EPDCCH can be obtained by increasing the aggregation level.

_{The n EPDCCH} , which is the quantity for a particular terminal device, is the following _{(in one PRB pair configured for EPDCCH transmission of EPDCCH set X 0} (the first EPDCCH set of up to two EPDCCH sets): It is defined as the number of downlink REs that satisfy all or part of the criteria a1) to (a4).
(A1) It is a part of any one of 16 EREGs in the PRB pair.
(A2) It is assumed that the terminal device does not use it as a CRS. Here, unless other values are provided for the number of antenna ports and frequency shift parameters of the CRS, these parameters in the serving cell are obtained based on the number of antenna ports and the physical cell identifier with the same antenna port settings as the PBCH. Frequency shift) gives the position of the CRS. On the contrary, when a set of these parameters is set in the terminal device by the upper layer parameter re-MappingQCL-ConfigID-r11, the position of the CRS is determined using the parameter.
(A3) It is assumed that the terminal device does not use it as CSIRS. Here, the position of the CSIRS is given by the setting of the zero power CSIRS in the serving cell (when no other value is provided for the setting for the zero power CSIRS) and the setting of the nonzero power CSIRS. On the contrary, when the zero power CSIRS is set in the terminal device by the upper layer parameter re-MappingQCL-ConfigID-r11, the position of the CSIRS is determined using the parameter.
_{(A4) Satisfy} that the index l in the first slot in the subframe is l EPDCCHStart or more. That is, it is mapped to RE on the OFDM symbol after _{l EPDCCHStart in one subframe.} Here, l is an index assigned to the OFDM symbol in the slot, and is assigned in ascending order from 0 in the time direction in order from the first OFDM symbol in the slot. l _EPDCCHStart will be described later.

In the second EPDCCH, an example of the correspondence between the EPDCCH format and the number of ECCEs (aggregation level) per EPDCCH is the same as that of the first EPDCCH.

In the second EPDCCH, one case is predetermined as another example of the correspondence between the EPDCCH format and the number of ECCEs (aggregation level) per EPDCCH. For example, in the second EPDCCH, the correspondence between the EPDCCH format and the number of ECCEs (aggregation level) per EPDCCH is defined in case A in advance.

In the second EPDCCH, another example of the correspondence between the EPDCCH format and the number of ECCEs per EPDCCH (aggregation level) can specify multiple cases of case A, case B, and case C. The aggregation level in case A and the aggregation level in case B are the same as those of the first EPDCCH. The aggregation level in case C can be higher than the aggregation level in case A. For example, the aggregation levels in Case C are 4, 8, 16 and 32 for local transmission and 4, 8, 16, 32 and 64 for distributed transmission.

_Further , in an example of n EPDCCH, which is a quantity for a specific terminal device _{, n EPDCCH} is independent of the first EPDCCH and the second EPDCCH. In the first EPDCCH, n _EPDCCH is within one PRB pair configured for EPDCCH transmission of EPDCCH set X ₀ (the first EPDCCH set of up to two EPDCCH sets) in the first EPDCCH. It is defined as the number of downlink REs that satisfy all of the criteria (a1) to (a4) above. Also, in the second EPDCCH, n _EPDCCH is within one PRB pair configured for EPDCCH transmission of EPDCCH set X ₀ (the first EPDCCH set of one or more EPDCCH sets) in the second EPDCCH. It is defined as the number of downlink REs that satisfy all or part of the criteria (a1) to (a4) above.

_Further , in an example of n EPDCCH which is a quantity for a specific terminal device _{, n EPDCCH} is common to the first EPDCCH and the second EPDCCH. Specifically, _{n EPDCCH} in the second EPDCCH is the same as _{n EPDCCH} in the first EPDCCH. That is, in the second EPDCCH, n _EPDCCH is within one PRB pair configured for EPDCCH transmission of EPDCCH set X ₀ (the first EPDCCH set of up to two EPDCCH sets) in the first EPDCCH. Therefore, it is defined as the number of downlink REs that satisfy all of the criteria (a1) to (a4) above.

_{B (0), ..., B (M bit} -1), which are blocks of bits transmitted on one EPDCCH in one subframe, are h (i) = (b (i) + c (i). ) Scrambled based on mod 2, resulting in a block of scrambled _bits h (0), ..., H (M bit -1). Here, M _bit is the number of bits transmitted by one EPDCCH, and c (i) is a scrambling sequence peculiar to the terminal device initialized by the _{parameter c init.} The scrambling sequence ^{_{generator, c init = floor (n s}} / 2) 2 9 + n EPDCCH ID, is _m. m is the EPDCCH set number. n _s is the slot number in the radio frame. n ^EPDCCH _{ID and m} are DMRS scrambling initialization parameters that can be set for each EPDCCH set by upper layer signaling, and can take any value from 0 to 503.

The scrambled bit blocks h (0), ..., H (M _bit -1) are modulated, resulting in complex value modulation d (0), ..., d (M _{symbol -1).} Become a block of symbols. Here, M _symb is the number of modulation symbols transmitted by one EPDCCH. The modulation method of EPDCCH is QPSK (Quadrature Phase Shift Keying). The complex value modulation symbol block is mapped and pre-recorded on a single layer based on the equation y (i) = d (i). Here, i = 0, ... It is M _symb -1, where y is a pre-recorded modulation symbol.

The blocks of complex symbols y (0), ..., Y (M _symb -1) are REs (k) on the associated antenna port such that they meet all of the criteria (m1) to (m4) below. It is mapped in order starting from y (0) to RE) at the position determined by and l.
(M1) Part of the EREG assigned for EPDCCH transmission.
(M2) It is assumed that the terminal device does not use it as a CRS. Here, unless other values are provided for the number of antenna ports and frequency shift parameters of the CRS, these parameters in the serving cell are obtained based on the number of antenna ports and the physical cell identifier with the same antenna port settings as the PBCH. Frequency shift) gives the position of the CRS. On the contrary, when a set of these parameters is set in the terminal device by the upper layer parameter re-MappingQCL-ConfigID-r11, the position of the CRS is determined using the parameter.
(M3) It is assumed that it will not be used as CSIRS by the terminal device. Here, the position of the CSIRS is given by the setting of the zero power CSIRS in the serving cell (when no other value is provided for the setting for the zero power CSIRS) and the setting of the nonzero power CSIRS. On the contrary, when the zero power CSIRS is set in the terminal device by the upper layer parameter re-MappingQCL-ConfigID-r11, the position of the CSIRS is determined using the parameter.
_{(M4) Satisfy} that the index l in the first slot in the subframe is l EPDCCHStart or more. That is, it is mapped to RE on the OFDM symbol after _{l EPDCCHStart in one subframe.} Here, l is an index assigned to the OFDM symbol in the slot, and is assigned in ascending order from 0 in the time direction in order from the first OFDM symbol in the slot. l _EPDCCHStart will be described later.

The mapping of the antenna port P to RE (RE at the position determined by k and l) that satisfies the above criteria is in ascending order (in the direction in which k and l increase) with respect to index k first and then index l. Starts in the first slot in the subframe and ends in the second slot.

Here, the antenna port P is a logical antenna port. One antenna port may correspond to one physical antenna, or the signal of one antenna port may actually be transmitted by a plurality of physical antennas. Alternatively, the signals of the plurality of antenna ports may actually be transmitted by the same physical antenna. If the antenna ports are the same, the same channel characteristics can be obtained. Here, antenna ports 0 to 3 are antenna ports associated with (used) transmission of CRS, and antenna port 4 is associated with (used) transmission of a reference signal for MBSFN (Multimedia Broadcast multiplicity Network). ) Antenna ports, antenna ports 5 and 7 to 14 are antenna ports (used) related to the transmission of PDSCH-related terminal device-specific reference signals, and antenna ports 107 to 110 are EPDCCH-related demodulations. Antenna ports associated with (used) transmission of the reference signal, antenna port 6 is the antenna port associated (used) with the transmission of the positioning reference signal, and antenna ports 15-22 are associated with the transmission of CSIRS. The antenna port (used).

In local transmission, the single antenna port P used is ^n'calculated _{by n'= n ECCE, low} mod N ^RB _ECCE + n _RNTI mod min (N _{EPDCCH ECCE} , N ^RB _ECCE ) and (n1) below. Is given by (n4). Here, n _{ECCE and low} are the lowest ECCE indexes used by this EPDCCH transmission in the EPDCCH set, and n _RNTI is equal to C-RNTI (Cell-RNTI) which is one of RNTI (Radio Network Identifier). .. Also, N ^EPDCCH _ECCE is the number of ECCEs used for this EPDCCH. Further, min is a maximum value function (max function).
(N1) In the case of a normal CP and a normal subframe or a special subframe setting 3, 4, or 8, n'= 0 corresponds to P = 107. In the case of a normal CP and a special subframe with special subframe settings 1, 2, 6, 7 or 9, n'= 0 corresponds to P = 107. In the case of extended CP, n'= 0 corresponds to P = 107 in any subframe type.
(N2) In the case of a normal CP and a normal subframe or a special subframe setting 3, 4, or 8, n'= 1 corresponds to P = 108. In the case of a normal CP and a special subframe with special subframe settings 1, 2, 6, 7 or 9, n'= 1 corresponds to P = 109. In the case of extended CP, n'= 1 corresponds to P = 108 in any subframe type.
(N3) In the case of a normal CP and a normal subframe or a special subframe setting 3, 4, or 8, n'= 2 corresponds to P = 109.
(N4) In the case of a normal CP and a normal subframe or a special subframe setting 3, 4, or 8, n'= 3 corresponds to P = 110.

In distributed transmission, each RE in one EREG starts at antenna port 107 and is associated with one of the two antenna ports according to alternating rules. Here, in the normal CP, the two antenna ports are the antenna port 107 and the antenna port 109, and in the extended CP, the two antenna ports are the antenna port 107 and the antenna port 108.

For each serving cell, the base station apparatus superimposes one or two EPDCCH-PRB sets (a set of PRB pairs in which EPDCCH can be placed, also referred to as EPDCCH set) for monitoring EPDCCH to the UE. It can be set by layer signaling. Here, a plurality of PRB pairs corresponding to one EPDCCH-PRB set (the number of PRB pairs corresponding to one EPDCCH-PRB set and which PRB pair the EPDCCH-PRB set corresponds to) are also in the upper layer. Indicated by signaling. Each EPDCCH-PRB set is composed of a set of ECCEs numbered from 0 to NECCE _{, p, k-} 1. Here, N _{ECCE, p, k} -1 is the number of ECCEs in the EPDCCH-PRB set p (p + 1th EPDCCH-PRB set, p is 0 or 1) in the subframe k. Each EPDCCH-PRB set can be configured with either local EPDCCH transmission or distributed EPDCCH transmission. That is, in the EPDCCH-PRB set in which local EPDCCH transmission is set, one EPDCCH is arranged relatively locally in the frequency direction, and in the EPDCCH-PRB set in which distributed EPDCCH transmission is set, one EPDCCH is frequency. It is arranged relatively distributed in the direction.

The EPDCCH set can be set independently for the first EPDCCH and the second EPDCCH. For example, the EPDCCH set for the first EPDCCH and the EPDCCH set for the second EPDCCH can be set using different parameters.

Further, the terminal may not set the EPDCCH set for the first EPDCCH and the EPDCCH set for the second EPDCCH at the same time in a certain serving cell. For example, the EPDCCH set for the first EPDCCH is set for the serving cell using conventional LTE, and the EPDCCH set for the second EPDCCH is set for the LAA cell. Further, for example, when a method (mode) in which one subframe is set as a unit in the time direction is set in the serving cell as in the conventional LTE, an EPDCCH set for the first EPDCCH is set. When a method (mode) in which one slot is set as a unit in the time direction is set, an EPDCCH set for a second EPDCCH is set.

Further, the terminal may set the EPDCCH set for the first EPDCCH and the EPDCCH set for the second EPDCCH at the same time in a certain serving cell. For example, in a LAA cell, in partial subframes, the first EPDCCH is monitored based on the EPDCCH set for the first EPDCCH, and in full subframes, based on the EPDCCH set for the second EPDCCH. The second EPDCCH is monitored.

An example in which the EPDCCH set for the first EPDCCH and the EPDCCH set for the second EPDCCH are set using different parameters is the number of PRB pairs that can be set corresponding to one EPDCCH set. For example, in the EPDCCH set for the first EPDCCH, the number of PRB pairs corresponding to one EPDCCH set can be set to 2, 4, or 8. In the EPDCCH set for the second EPDCCH, the number of PRB pairs that can be set for one EPDCCH set is 4, 8, or 16 which is twice that of the EPDCCH set for the first EPDCCH. is there. Further, in the EPDCCH set for the second EPDCCH, the number of PRB pairs corresponding to one EPDCCH set may be determined according to the assumed start symbol or end symbol of the second EPDCCH. .. For example, the smaller the number of OFDM symbols used to transmit the second EPDCCH, the greater the number of PRB pairs corresponding to one EPDCCH set.

An example in which the EPDCCH set for the first EPDCCH and the EPDCCH set for the second EPDCCH are set using different parameters is a parameter relating to a partial subframe. For example, the start symbol and / or end symbol of the second EPDCCH, or a parameter indicating a candidate thereof is included.

Further, an example of the start symbol of the second EPDCCH is set independently or in common for each EPDCCH set through RRC signaling. For example, one of the OFDM symbols # 0 to 6 in slot 0 and the OFDM symbols # 0 to 6 in slot 1 is set as the start symbol of the second EPDCCH. Further, for example, as the start symbol of the second EPDCCH, a predetermined number from the OFDM symbols # 0 to 6 in slot 0 and the OFDM symbols # 0 to 6 in slot 1 are defined in advance as candidates, and any one of the candidates. One is set. Further, for example, either the OFDM symbol # 0 in slot 0 or the OFDM symbol # 0 in slot 1 is set as the start symbol of the second EPDCCH. Further, for example, the start symbol of the second EPDCCH is determined based on the OFDM symbol in which the initial signal is detected. Specifically, the start symbol of the second EPDCCH is an OFDM symbol in which the initial signal is detected, or an OFDM symbol after a predetermined number from the OFDM symbol in which the initial signal is detected. Further, for example, the start symbol of the second EPDCCH is an OFDM symbol in which a plurality of candidates are specified or set, and is the latest OFDM symbol after the OFDM symbol in which the initial signal is detected.

Further, an example of the end symbol of the second EPDCCH is set independently or in common for each EPDCCH set through RRC signaling. For example, as the end symbol of the second EPDCCH, any one of the OFDM symbols # 0 to 6 in slot 0 and the OFDM symbols # 0 to 6 in slot 1 are set. Further, for example, as the end symbol of the second EPDCCH, a predetermined number from the OFDM symbols # 0 to 6 in slot 0 and the OFDM symbols # 0 to 6 in slot 1 are defined in advance as candidates, and any one of the candidates. One is set. Further, for example, as the end symbol of the second EPDCCH, either the OFDM symbol # 6 in slot 0 or the OFDM symbol # 6 in slot 1 is set. Also, for example, the end symbol of the second EPDCCH is determined based on the start symbol of the second EPDCCH in the burst. Also, for example, the end symbol of the second EPDCCH is determined based on the start symbol of the second EPDCCH in the burst and the maximum length of the burst. Further, for example, the end symbol of the second EPDCCH is determined based on the control information included in the initial signal in the burst. Specifically, the control information includes information indicating an end symbol of the second EPDCCH. Also, for example, the end symbol of the second EPDCCH is determined based on the control information contained in the predetermined channel and / or signal transmitted in that subframe.

The terminal device monitors a set of EPDCCH candidates in one or more valid serving cells as set by higher layer signaling for control information. Here, monitoring implies trying to decode each EPDCCH in the set of EPDCCH candidates according to the DCI format to be monitored. The EPDCCH USS (UE-specific Search Space) defines a set of EPDCCH candidates to be monitored. Here, the USS is a logical area set unique to the terminal device and is an area that can be used for transmission of downlink control information. Monitoring is also referred to as blind detection.

Further, the start symbol of the second EPDCCH and / or the end symbol of the second EPDCCH may be blindly detected (monitored) by the terminal from a plurality of OFDM symbol candidates. For example, it is assumed that the terminal has specified or set a plurality of candidates for the start symbol of the second EPDCCH and / or the end symbol of the second EPDCCH, and transmitted based on the OFDM symbols that are the candidates. Monitor 2 EPDCCH. That is, each of the second EPDCCHs in the second set of EPDCCH candidates may have independent (or different) assumed start and / or end symbols.

For each serving cell, the subframe in which the UE monitors the EPDCCH USS is set by the upper layer. More specifically, for an FDD half-duplex terminal device during active time (a period that is not an inactive timer activation period due to intermittent reception, a period that is not a non-reception period, the total period during which the terminal device is awake). In subframes that are not required for uplink transmission and are not part of the measurement gap, the upper layer configures EPDCCH monitoring. Here, intermittent reception means that the terminal device does not need to be awake (active) (may be inactive) except for a part of the period in order to optimize the battery consumption of the terminal device. ). The FDD (Frequency Division Duplex) half-duplex terminal device is a terminal device that does not have a function of simultaneously performing uplink transmission and downlink reception (in the same subframe) in the FDD band. The measurement gap is a period during which transmission / reception is stopped in the serving cell in order to perform measurement for mobility (handover) (measurement of received power of cells other than the serving cell), and the measurement gap pattern is set by RRC. ..

The terminal device does not monitor EPDCCH in the following cases (e1) to (e4).
(E1) In the case of TDD and normal downlink CP, the special subframes with special subframe settings 0 and 5 (special subframes in which the number of OFDM symbols in DwPTS is less than 6).
(E2) In the case of TDD and extended downlink CP, special subframes with special subframe settings 0, 4, and 7 (special subframes in which the number of OFDM symbols in DwPTS is less than 6).
(E3) When the subframe is instructed to decode PMCH (Physical Multicast Channel) by the upper layer.
(E4) TDD and different UL / DL settings are set for the primary cell and the secondary cell, the downlink subframe in the secondary cell, the same subframe in the primary cell is the special subframe, and the terminal device is the primary cell. When there is no ability to send and receive at the same time between

Here, the special subframe is a subframe including three areas in the order of the area for performing downlink transmission (DwPTS), the guard period (GP), and the area for performing uplink transmission (UpPTS) in one subframe. Therefore, the lengths of DwPTS, GP, and UpPTS are uniquely determined by the special subframe setting and the CP length. The PMCH is a channel for providing the MBMS (Multicast / Multicast Service) service and can be arranged only in the MBSFN subframe.

The special subframe setting is set to any one of the following 10 settings.
With the special subframe setting 0, the DwPTS is 6592 samples in the normal downlink CP, the UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 7680 samples, UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. DwPTS is composed of three OFDM symbols, and UpPTS is composed of one SC-FDMA symbol.
In the special subframe setting 1, the DwPTS is 19760 samples in the normal downlink CP, the UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 20480 samples, UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. DwPTS is composed of 9 OFDM symbols in the case of a normal downlink CP and 8 in the case of an extended downlink CP, and UpPTS is composed of one SC-FDMA symbol.
In the special subframe setting 2, the DwPTS is 21952 samples in the normal downlink CP, the UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 23040 samples, UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. DwPTS is composed of 10 OFDM symbols in the case of a normal downlink CP and 9 in the case of an extended downlink CP, and UpPTS is composed of one SC-FDMA symbol.
In the special subframe setting 3, the DwPTS is 24144 samples in the normal downlink CP, the UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 25600 samples, UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. DwPTS is composed of 11 OFDM symbols in the case of a normal downlink CP and 10 in the case of an extended downlink CP, and UpPTS is composed of one SC-FDMA symbol.
In the special subframe setting 4, the DwPTS is 26336 samples in the normal downlink CP, the UpPTS is 2192 samples in the normal uplink CP, and 2560 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 7680 samples, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 12 OFDM symbols in the case of normal downlink CP and 3 in the case of extended downlink CP, and UpPTS is composed of 1 SC-FDMA symbol in the case of normal downlink CP. , In the case of extended downlink CP, it is composed of two SC-FDMA symbols.
In the special subframe setting 5, the DwPTS is 6592 samples in the normal downlink CP, the UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 20480 samples, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 3 OFDM symbols in the case of normal downlink CP and 8 in the case of extended downlink CP, and UpPTS is composed of 2 SC-FDMA symbols.
In the special subframe setting 6, the DwPTS is 19760 samples in the normal downlink CP, the UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 23040 samples, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 9 OFDM symbols, and UpPTS is composed of 2 SC-FDMA symbols.
In the special subframe setting 7, the DwPTS is 21952 samples in the normal downlink CP, the UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. On the other hand, in the extended downlink CP, DwPTS is 12800 samples, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 10 OFDM symbols in the case of a normal downlink CP and 5 in the case of an extended downlink CP, and UpPTS is composed of 2 SC-FDMA symbols.
In the special subframe setting 8, DwPTS is 24144 samples in the normal downlink CP, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 11 OFDM symbols in the case of a normal downlink CP, and UpPTS is composed of 2 SC-FDMA symbols.
In the special subframe setting 9, DwPTS is 13168 samples in the normal downlink CP, UpPTS is 4384 samples in the normal uplink CP, and 5120 samples in the extended uplink CP. DwPTS is composed of 6 OFDM symbols in the case of a normal downlink CP, and UpPTS is composed of 2 SC-FDMA symbols.

Here, when UpPTS is composed of one SC-FDMA symbol, the terminal device uses the one SC-FDMA symbol as a reference for uplink sounding in response to a request from the base station device. A signal, SRS (Sounding Reference Symbol), can be transmitted. When UpPTS is composed of two SC-FDMA symbols, the terminal device can transmit SRS using at least one of the two SC-FDMA symbols in response to a request from the base station device. ..

Here, in a normal CP, a normal downlink subframe is composed of 14 OFDM symbols, and a normal uplink subframe is composed of 14 SC-FDMA symbols. Further, in the extended CP, the normal downlink subframe is composed of 12 OFDM symbols, and the normal uplink subframe is composed of 12 SC-FDMA symbols.

Further, the UL / DL setting is set to any one of the following seven settings.
In UL / DL setting 0, subframes 0 to 9 in one wireless frame (10 subframes) are sequentially downlink subframe, special subframe, uplink subframe, uplink subframe, and uplink. Subframes, downlink subframes, special subframes, uplink subframes, uplink subframes, and uplink subframes. The period of the conversion point from the downlink to the uplink is 5 subframes (5 milliseconds).
In UL / DL setting 1, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, uplink subframe, downlink subframe, and downlink, respectively. Subframes, special subframes, uplink subframes, uplink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 5 subframes.
In UL / DL setting 2, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, downlink subframe, downlink subframe, and downlink. Subframes, special subframes, uplink subframes, downlink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 5 subframes.
In UL / DL setting 3, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, uplink subframe, uplink subframe, and downlink. Subframes, downlink subframes, downlink subframes, downlink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 10 subframes (10 milliseconds).
In UL / DL setting 4, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, uplink subframe, downlink subframe, and downlink, respectively. Subframes, downlink subframes, downlink subframes, downlink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 10 subframes.
In UL / DL setting 5, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, downlink subframe, downlink subframe, and downlink. Subframes, downlink subframes, downlink subframes, downlink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 10 subframes.
In UL / DL setting 6, subframes 0 to 9 in one wireless frame are sequentially downlink subframe, special subframe, uplink subframe, uplink subframe, uplink subframe, and downlink. Subframes, special subframes, uplink subframes, uplink subframes, and downlink subframes. The period of the conversion point from the downlink to the uplink is 5 subframes.

Here, when the UL / DL setting for at least one serving cell is the UL / DL setting 5, no more than two serving cells are set.

^{ES (L)} _k, which is the USS of EPDCCH at aggregation level L, is defined by a set of EPDCCH candidates. Here, L is any of 1, 2, 4, 8, 16 and 32. For one EPDCCH-PRB set p, the ECCE corresponding to the EPDCCH candidate m of ^{the search space ES (L)} _{k is L ((Y p, k} + floor (mN _{ECCE, p, k} / (LM ^(L) _{p) p.} )) + B) mod (floor (N _{ECCE, p, k} / L))) + i. Here, i = 0, ..., L-1. Further, when CIF (Carrier Indicator Field) is set for the serving cell on which EPDCCH is monitored, b is the value of CIF, and b = 0 in other cases. Further, m = 0, 1, ..., M ^(L) _p -1. If no CIF is set for the serving cell on which the EPDCCH is monitored, M ^(L) _p is the number of EPDCCHs to be monitored at the aggregation level L in the EPDCCH-PRB set p in that serving cell on which the EPDCCH is monitored. .. Otherwise, M ^(L) _p is the number of EPDCCHs to be monitored at aggregation level L in the EPDCCH-PRB set p in the serving cell indicated by the value of CIF. Here, the CIF is a field in the DCI format, and the value of the CIF is used to determine which serving cell the DCI format corresponds to the PDSCH transmission, PUSCH transmission, or random access procedure of the primary cell or the primary cell. Takes the same value as the serving cell index corresponding to any of the secondary cells.

If within the same subframe, the ECCE corresponding to an EPDCCH candidate is mapped to a PRB pair that overlaps in frequency with the transmission of either the PBCH, the primary sync signal or the secondary sync signal, the terminal device is that EPDCCH. Do not monitor candidates.

The terminal device has the same value of n ^EPDCCH _{ID, i} set in two EPDCCH-PRB sets, and the terminal device is an EPDCCH candidate of a certain DCI payload size corresponding to one EPDCCH-PRB set. An EPDCCH candidate that receives an EPDCCH candidate mapped to a RE set and whose terminal device is an EPDCCH candidate of the same DCI payload size corresponding to the other EPDCCH-PRB set and that is mapped to the same RE set. If monitoring is also set and the first ECCE number of the received EPDCCH is used to determine the PUCCH resource for HARQ-ACK transmission, then the first ECCE number is p = Determined based on the EPDCCH-PRB set of 0. Here, n ^EPDCCH _{ID and i} are parameters used for initializing the pseudo-random sequence generation of DMRS (Demodulation Reference Signal) related to EPDCCH, and are set by the upper layer. In addition, i takes a value of 0 or 1, and indicates which EPDCCH set the EPDCCH related to DMRS belongs to. That is, it is almost synonymous with p.

Y _{p, k} is defined by Y _{p, k} = (A _p Y _{p, k-1} ) modD. Here, Y _{p and -1} are values of RNTI, which is an identifier set in the terminal device in the physical layer, A ₀ is 39827, A ₁ is 39829, D is 65537, and k = floor. ( _Ns / 2). That is, since each subframe is composed of two slots, k indicates the subframe number in the radio frame.

In addition, the correspondence between the number of PRBs included in the EPDCCH-PRB set, the aggregation level, and the number of EPDCCH candidates to be monitored can be defined. The aggregation level that defines the search space and the number of EPDCCH candidates to be monitored is given as follows. ^{Here, N} _{Xp RB} is the number of PRB pairs constituting the EPDCCH-PRB set p.

Here, the aggregation level that defines the search space and the number of EPDCCH candidates to be monitored is (1) when only one EPDCCH-PRB for distributed transmission is set in the terminal device, and (2) the terminal device. When only one EPDCCH-PRB for local transmission is set in, (3) when two EPDCCH-PRBs for distributed transmission are set in the terminal device, (4) in the terminal device. When two EPDCCH-PRBs for local transmission are set, (5) one EPDCCH-PRB for distributed transmission and one EPDCCH-PRB for local transmission are installed in the terminal device. If is set, each can be specified independently.

In the present embodiment, p1 is a code for identifying the local EPDCCH-PRB set, p1 is a code for identifying the local EPDCCH-PRB set, and p2 is a code for identifying the distributed EPDCCH-PRB set. Is. That is, N ^Xp1 _RB is the number of PRB pairs that make up the local EPDCCH-PRB set, and N ^Xp2 _RB is the number of PRB pairs that make up the distributed EPDCCH-PRB set. Also, M ^(L) _p1 is the number of EPDCCHs to be monitored at the aggregation level L in the local EPDCCH-PRB set, and M ^(L) _p2 should be monitored at the aggregation level L in the distributed EPDCCH-PRB set. The number of EPDCCH.

Regarding the correspondence between the number of PRBs included in the EPDCCH-PRB set, the aggregation level, and the number of EPDCCH candidates to be monitored, case 1 is the case of the following (c1) to (c4), and case 1 is the case of the following (c5) to (c7). In the case of (c8), case 2 is applied, and in the case of (c8), case 3 is applied.
(C1) When either DCI format 2, 2A, 2B, 2C, or 2D is monitored in a normal subframe and a normal downlink CP, and the M ^DL _RB is 25 or more. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively large and the payload size of the DCI format is very large.
(C2) Special subframe setting 3, 4 or 8 special subframe and normal downlink CP (that is, a special subframe in which DwPTS is composed of 11 or more OFDM symbols), DCI format 2, 2A, 2B, When either 2C or 2D is monitored and the M ^DL _RB is 25 or more. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively large and the payload size of the DCI format is very large.
(C3) DCI format 1A, 1B, 1D, 1, 2, 2A, 2B, 2C, 2D, 0 or 4 is monitored in a normal subframe and a normal downlink CP, and n _EPDCCH is 104. If smaller. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is very small.
(C4) Special subframe setting 3, 4 or 8 special subframe and normal downlink CP (that is, a special subframe in which DwPTS is composed of 11 or more OFDM symbols), DCI format 1A, 1B, 1D, When any of 1, 2, 2A, 2B, 2C, 2D, 0 or 4 is monitored and n _EPDCCH is less than 104. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is very small.
(C5) When any of DCI formats 1A, 1B, 1D, 1, 2, 2A, 2B, 2C, 2D, 0 or 4 is monitored in a normal subframe and extended downlink CP. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively small.
(C6) Special subframe setting A special subframe of 1, 2, 6, 7 or 9 and a normal downlink CP (that is, a special subframe composed of OFDM symbols having 6 or more and 10 or less DwPTS). When any of DCI formats 1A, 1B, 1D, 1, 2, 2A, 2B, 2C, 2D, 0 or 4 is monitored. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively small.
(C7) Special subframe setting 1, 2, 3, 5 or 6 special subframe and extended downlink CP (that is, a special subframe composed of OFDM symbols having 6 or more and 10 or less DwPTS). When any of DCI formats 1A, 1B, 1D, 1, 2, 2A, 2B, 2C, 2D, 0 or 4 is monitored. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively small.
(C8) When neither of the above (c1) to (c7) is performed. That is, when the number of REs that can be used for EPDCCH transmission in one PRB pair is relatively large and the payload size of the DCI format is not so large.

Here, when the terminal device does not set the CIF for the serving cell in which the EPDCCH is monitored, the M ^DL _RB ^{is the N DL} _RB of the serving cell in which the EPDCCH is monitored. If the terminal device has a CIF set for the serving cell on which the EPDCCH is monitored, the M ^DL _RB ^{is the N DL} _RB of the serving cell specified by the value of the CIF. Here, N ^DL _RB is a downlink bandwidth setting and is expressed in multiples of the resource block size in the frequency direction. In other words, N ^DL _RB is the total number of resource blocks in the frequency direction within the downlink component carrier in the serving cell. Further, DCI formats 1A, 1B, 2D, and 1 are DCI formats used in a transmission mode in which one transport block can be transmitted using one PDSCH, and are transmission diversity and a closed loop using a single port, respectively. It is used in PDSCH transmission methods such as spatial multiplexing, multi-user MIMO (Multiple MIMO), and single antenna port transmission. The DCI formats 2, 2A, 2B, 2C, and 2D are DCI formats used in a transmission mode in which up to two transport blocks can be transmitted using one PDSCH, and are closed-loop space multiplexing and large-delay CDD, respectively. (Cyclic Delay Diversity), which is used in a PDSCH transmission method of 2-layer transmission, 8-layer or less transmission, and 8-layer or less transmission. Further, DCI formats 2 and 2A are further used in the PDSCH transmission method of transmission diversity, and DCI formats 2B, 2C and 2D are further used in the PDSCH transmission method of a single antenna port. DCI formats 0 and 4 are DCI formats used in transmission modes in which one and up to two transport blocks can be transmitted using one PUSCH, respectively, for single antenna port transmission and closed-loop spatial multiplexing, respectively. It is used in the PDSCH transmission method.

The transmission mode is a mode that is quasi-statically set in the terminal device in order to receive PDSCH data transmission signaled via PDCCH or EPDCCH via upper layer signaling. As the transmission mode, any one of the following transmission modes 1 to 10 is set.
In the transmission mode 1, a PDSCH transmission method of single antenna port transmission (transmission by antenna port 0) is used, and DCI format 1 or 1A is used.
In the transmission mode 2, the PDSCH transmission method of the transmission diversity is used, and DCI format 1 or 1A is used.
In the transmission mode 3, a large-delay CDD or a PDSCH transmission method of transmission diversity is used, and DCI format 1 or 2A is used.
In the transmission mode 4, a closed-loop space multiplexing or transmission diversity PDSCH transmission method is used, and DCI format 1 or 2 is used.
In the transmission mode 5, a multi-user MIMO or a transmission diversity PDSCH transmission method is used, and DCI format 1 or 1D is used.
In the transmission mode 6, a closed-loop spatial multiplexing or transmission diversity PDSCH transmission method using a single port is used, and DCI format 1 or 1B is used.
In the transmission mode 7, a PDSCH transmission method of either single antenna port transmission (transmission by antenna port 5) or transmission diversity or single antenna port transmission (transmission by antenna port 0) is used, and DCI format 1 or 1 is used. Be done.
Transmission mode 8 uses a PDSCH transmission method of either two-layer transmission (transmission via antenna port 7 and antenna port 8) or transmission diversity or single antenna port transmission (transmission via antenna port 0), DCI format 1 or 2B. Is used.
The transmission mode 9 is either transmission of 8 layers or less (transmission from antenna port 7 to antenna port 14) or transmission diversity or single antenna port transmission (transmission by antenna port 0) (however, in the case of MBSFN subframe, antenna port 7). PDSCH transmission method (single antenna port transmission by) is used, and DCI format 1 or 2C is used.
The transmission mode 10 is either transmission of 8 layers or less (transmission from antenna port 7 to antenna port 14) or transmission diversity or single antenna port transmission (transmission by antenna port 0) (however, in the case of MBSFN subframe, antenna port 7). PDSCH transmission method (single antenna port transmission by) is used, and DCI format 1 or 2C is used.

In addition, other transmission modes (for example, transmission mode 11 according to the same regulations as transmission modes 9 and 10) may be used. For example, the transmission mode 11 uses the DCI format used in the LAA cell. As the transmission mode 11, the processing method, coding method, transmission method, and / or reception method in the LAA cell described in the present embodiment are used.

If the terminal device is not configured with a CIF, the terminal device is set to monitor the EPDCCH at each aggregation level given by the correspondence table of FIGS. X1 to X10 in each activated serving cell. Monitor the USS of one EPDCCH. If the terminal device is configured for EPDCCH monitoring and the terminal device is configured for CIF, the terminal device is one or more activated serving cells as set by higher layer signaling. In, the USS of one or more EPDCCHs at each aggregation level given by the correspondence table of FIGS. X1 to X10 is monitored. The terminal device in which the CIF related to the monitoring of the EPDCCH in the serving cell c is set monitors the EPDCCH in which the CIF is set and the CRC scrambled by C-RNTI is added in the USS of the EPDCCH in the serving cell c. The terminal device in which the CIF related to the monitoring of the EPDCCH in the primary cell is set is added with the CRC in which the CIF is set and scrambled by SPS-RNTI (Semi Persist Scheduling-RNTI) in the USS of the EPDCCH of the primary cell. Monitor the EPDCCH that has been created. Here, C-RNTI is an RNTI used for EPDCCH transmission related to dynamic PDSCH transmission or PUSCH transmission, and SPS-RNTI is an RNTI used for EPDCCH transmission related to quasi-steady PDSCH transmission or PUSCH transmission. is there.

In the serving cell where the EPDCCH is monitored, if the terminal device is not set to CIF, the terminal device monitors the USS of the EPDCCH for the EPDCCH that does not contain the CIF, and if the terminal device is set to CIF, that. The terminal device monitors the USS of the EPDCCH for the EPDCCH containing the CIF. That is, depending on whether or not the CIF is set, it is determined whether the EPDCCH decodes the EPDCCH assuming that the EPDCCH contains the CIF or the EPDCCH decodes the EPDCCH assuming that the EPDCCH does not contain the CIF. If the terminal device is configured to monitor an EPDCCH containing a CIF corresponding to a secondary cell in another serving cell, the terminal difference does not monitor the EPDCCH in that secondary cell. In a serving cell where the EPDCCH is monitored, the terminal device monitors EPDCCH candidates for at least the same serving cell.

A terminal device set to monitor an EPDCCH candidate on a serving cell of a DCI format size including a CIF with a CRC scrambled by C-RNTI may be CIF-capable at that DCI format size. It is assumed that in any EPDCCH USS corresponding to any value, EPDCCH candidates of that DCI format size may be transmitted on that serving cell.

When the transmission opportunity of the positioning reference signal is set only in the MBSFN subframe for the serving cell in which the EPDCCH is monitored, and the CP length used in the subframe 0 is a normal CP, the terminal device sets the positioning reference signal. The monitoring of EPDCCH is not required in the subframe set for the upper layer as part of the transmission opportunity of.

Terminal device, while monitoring the EPDCCH candidates associated with any of the antenna ports 107 and 108, the value of the same _{C init} is assumed that used in the antenna port 107 and 108. Terminal device, while monitoring the EPDCCH candidates associated with any of the antenna ports 109 and 110, the value of the same _{C init} is assumed that used in the antenna port 109 and 110.

When the terminal device is set to receive the PDSCH data transmission according to the transmission modes 1 to 9 for a serving cell via the upper layer signaling, the terminal device is set to the following (s1) and Follow (s2).
(S1) When the upper layer parameter epdcch-StartSymbol-r11 is set in the terminal device, the start OFDM symbol for EPDCCH given by _{l EPDCCHStart, which is an index in the first slot in one subframe.} (The first OFDM symbol to which the EPDCCH is mapped in one subframe, also called the start position of the EPDCCH) is determined from its upper layer parameters. Here, the upper layer parameter epdcch-StartSymbol-r11 is a parameter that can be individually set for each EPDCCH set, and is a parameter (information indicating the start OFDM symbol) for designating the start OFDM symbol of the EPDCCH. The upper layer parameter epdcch-StartSymbol-r11 is set using the RRC message.
(S2) Otherwise, the starting OFDM symbol for _EPDCCH , given by the index l EPDCCHStart in the first slot in one subframe, is that subframe of that serving cell if ^{N DL} _{RB is greater than 10.} It is given by the value of CFI (Control Format Indicator) in, and when N ^DL _RB is 10 or less, it is given by adding 1 to the value of CFI in the subframe of the serving cell. Here, the CFI is a parameter that takes any one of 1, 2 and 3 as a value, and is control information transmitted and received via PCFICH (Physical CFI Channel). CFI is information about the number of OFDM symbols used for transmission of PDCCH in one subframe.

When the terminal device is set to receive PDSCH data transmission according to the transmission mode 10 for a certain serving cell via upper layer signaling, for each EPDCCH ^ PRB set, in the subframe k. The starting OFDM symbol for monitoring EPDCCH follows the upper layer parameter pdsch-Start-r11, as in (s3) to (s6) below. Here, the upper layer parameter pdsch-Start-r11 is a parameter that can be individually set for the four types of parameter sets for PDSCH, and is a parameter for designating the start OFDM symbol of PDSCH (start OFDM symbol). Information to be shown). The upper layer parameter pdsch-Start-r11 is set using the RRC message.
(S3) If the value of pdsch-Start-r11 belongs to the set of 1, 2, 3 and 4 (the value is one of 1, 2, 3 and 4), then l' _EPDCCHStart is pdsch-Start- Given by r11.
(S4) In other cases (when the value of pdsch-Start-r11 does not belong to the set 1, 2, 3 and 4), l' _EPDCCHStart is a subframe of its serving cell if ^{N DL} _{RB is greater than 10.} Given by the value of CFI at k, l' _EPDCCHStart is given by adding 1 to the value of CFI at subframe k of the serving cell when ^{N DL} _{RB is 10 or less.}
(S5) If the subframe k is a subframe specified by the upper layer parameter mbsfn-SubframeConfigList-r11, or if the subframe k is a subframe 1 or 6 in a subframe configuration for TDD, then l _EPDCCHStart , L _EPDCCHStart = min (2, l' _EPDCCHStart ).
(S6) Other cases (when the subframe k is not the subframe specified by the upper layer parameter mbsfn-SubframeConfigList-r11, and the subframe k is not the subframe 1 or 6 in the subframe configuration for TDD. ), L _EPDCCHStart is given by _{l EPDCCHStart} = l' _EPDCCHStart.

When the terminal device is set to receive the PDSCH data transmission according to the transmission modes 1 to 9 and the EPDCCH monitor is set for a certain serving cell, the terminal device is set to receive the PDSCH data transmission according to the transmission modes 1 to 9. The terminal device assumes that antenna ports 0 to 3 and 107 to 110 in its serving cell are pseudo-colocated with respect to Doppler shift, Doppler spread, average delay and delay spread (assuming they are transmitted from the same transmission point). Receive as if it was not transmitted from a different transmission point).

When the terminal device is set to receive the PDSCH data transmission according to the transmission mode 10 and the EPDCCH monitor is set for a certain serving cell, each EPDCCH- The following (q1) and (q1) apply to the PRB set.
(Q1) When the terminal device is configured by the upper layer to decode the PDSCH based on the pseudo-collocation type A, the terminal device has antenna ports 0 to 3 and 107 to 110 in the serving cell. Suppose it is pseudo-collocation with respect to Doppler shifts, Doppler spreads, average delays and delay spreads.
(Q2) When the terminal device is set by the upper layer to decode the PDSCH based on the pseudo-colocation type B, the terminal device is set to the upper layer parameter qcl-CSI-RS-ConfigNZPId-r11. It is assumed that the corresponding antenna ports 15 to 22 and 107 to 110 are pseudocolocates with respect to Doppler shifts, Doppler spreads, average delays and delay spreads. Here, the upper layer parameter qcl-CSI-RS-ConfigNZPId-r11 is a parameter that can be individually set for the four types of parameter sets for PDSCH, and is a parameter (PDSCH) for specifying pseudo collocation of PDSCH. Information indicating which CSIRS the terminal-specific reference signal related to is pseudo-collocated with). The upper layer parameter qcl-CSI-RS-ConfigNZPId-r11 is set using the RRC message.
Here, the pseudo collocation type A and the pseudo collocation type B are parameters in which any one of the pseudo collocation type A and the pseudo collocation type B is set for each serving cell with respect to the terminal device in which the transmission mode 10 is set. Indicates that the serving cell is pseudo-collocated with CRS antenna ports 0-3, type B indicates that antenna ports 7-14 are pseudo-collocated with any CSIRS antenna port 15-22. Conversely, when type B is set, CSIRS is not necessarily transmitted from the base station device corresponding to the serving cell, but may be transmitted from another base station device. In that case, the EPDCCH or PDSCH pseudo-colocated with the CSIRS is usually transmitted from the same transmission point as the CSIRS (for example, a remote overhang antenna device or another base station device connected to the base station device by a backhaul). Has been done.

When the terminal device is set to receive PDSCH data transmission according to the transmission mode 10 and the EPDCCH monitor is set for a certain serving cell, each EPDCCH- For the PRB set, the terminal uses the parameters specified by the upper layer parameter MappingQCL-ConfigId-r11 for RE mapping of its EPDCCH and determination of antenna port pseudo-collocation. The parameter set includes the following parameters (Q1) to (Q6) for determining EPDCCH RE mapping and antenna port pseudo-collocation.
(Q1) crs-PortsCount-r11. crs-PortsCount-r11 is a parameter indicating the number of CRS ports used when mapping PDSCH or EPDCCH to RE.
(Q2) crs-FreqShift-r11. crs-FreqShift-r11 is a parameter indicating the frequency shift of CRS used when mapping PDSCH or EPDCCH to RE.
(Q3) mbsdn-SubframeConfigList-r11. mbsdn-SubframeConfigList-r11 is a parameter indicating the position of the MBSFN subframe used when mapping PDSCH or EPDCCH to RE. In the subframe set as the MBSFN subframe with this parameter, PDSCH and EPDCCH are assumed to exist only in the OFDM symbols in which PDCCH can be placed (assuming that CRS does not exist in OFDM symbols in which PDCCH is not placed). It is mapped.
(Q4) csi-RS-ConfigZPId-r11. csi-RS-ConfigZPId-r11 is a parameter indicating the position of zero power CSIRS used when mapping PDSCH or EPDCCH to RE.
(Q5) pdsch-Start-r11. pdsch-Start-r11 is a parameter indicating a start OFDM symbol used when mapping PDSCH or EPDCCH to RE.
(Q6) qcl-CSI-RS-ConfigNZPId-r11. The qcl-CSI-RS-ConfigNZPId-r11 is a parameter indicating which CSIRS the reference signal for demodulating the PDSCH or EPDCCH is collated with. This parameter can specify any ID of one or more CSIRSs set. It is assumed that the reference signal for demodulating the PDSCH or EPDCCH is pseudo-colocated with the CSIRS whose ID is specified.

Next, the PDSCH scheduled by the second EPDCCH will be described. An example of a PDSCH scheduled in a second EPDCCH is only a PDSCH in which the second EPDCCH is mapped to a detected (mapped) subframe.

Another example of a PDSCH scheduled on a second EPDCCH includes a PDSCH that is mapped to any subframe in the burst that contains the detected (mapped) subframe of the second EPDCCH. Information (setting) regarding the subframe to which the PDSCH is mapped may be set by RRC or may be notified through DCI transmitted by the second EPDCCH. Further, the PDSCH scheduled by the second EPDCCH may be one subframe or a plurality of subframes.

Next, when the PDSCH scheduled in the second EPDCCH is mapped to a partial subframe, the start symbol and / or end symbol of the PDSCH will be described. For example, the start symbol and / or end symbol of the PDSCH is determined based on the control information contained in the DCI in the second EPDCCH to be scheduled. Also, for example, the start symbol and / or end symbol of the PDSCH is determined based on the start symbol and / or end symbol of the second EPDCCH to be scheduled. Also, for example, the start symbol and / or end symbol of the PDSCH is the same as the start symbol and / or end symbol of the second EPDCCH to be scheduled. Also, for example, the PDSCH start symbol and / or end symbol is an OFDM symbol calculated from the scheduled second EPDCCH start symbol and / or end symbol. Also, for example, the PDSCH start and / or end symbol is set through RRC signaling independently of the scheduling second EPDCCH start and / or end symbol. Further, for example, the start symbol and / or end symbol of the PDSCH is determined by the control information contained in the physical channel or physical signal mapped to the subframe. Further, the start symbol and the end symbol of the PDSCH may have different determination methods or notification methods.

Further, the setting regarding the subframe for monitoring the first EPDCCH for the first EPDCCH set and the setting for the subframe for monitoring the second EPDCCH for the second EPDCCH set may be different from each other. For example, the subframe for monitoring the first EPDCCH is set in common for all the first EPDCCH sets, and whether or not to monitor for each subframe is set by the information in the bitmap format. An example of the setting for the subframe for monitoring the second EPDCCH is the same as the setting for the subframe for monitoring the first EPDCCH, but is set independently. Another example of the setting relating to the subframe for monitoring the second EPDCCH is to monitor the second EPDCCH in the subframe in which the terminal detects a burst (downlink burst transmission) in the LAA cell.

Some of the embodiments described above can be paraphrased as follows.

In the terminal device of the present embodiment, the first serving cell has a first EPDCCH set for monitoring the first EPDCCH, and the second serving cell has a second EPDCCH set for monitoring the second EPDCCH. It includes an upper layer processing unit to be set and a receiving unit that monitors the first EPDCCH and the second EPDCCH. The start symbol of the first EPDCCH and the start symbol of the second EPDCCH in a certain subframe are determined independently.

The base station apparatus of the present embodiment has a first EPDCCH set for monitoring the first EPDCCH in the first serving cell and a second EPDCCH set for monitoring the second EPDCCH in the second serving cell. It is provided with an upper layer processing unit for setting the above in the terminal device and a transmission unit for transmitting the first EPDCCH and the second EPDCCH. The start symbol of the first EPDCCH and the start symbol of the second EPDCCH in a certain subframe are determined independently.

The maximum value that can be set for the start symbol of the second EPDCCH is larger than the maximum value that can be set for the start symbol of the first EPDCCH. For example, the values that can be set for the start symbol of the first EPDCCH are 1, 2, 3, or 4. The value that can be set for the start symbol of the second EPDCCH includes a value different from the value that can be set for the start symbol of the first EPDCCH.

The start symbol of the first EPDCCH is set based on the parameters of the upper layer. The start symbol of the second EPDCCH is determined based on the symbol that detects the initial signal. For example, the start symbol of the second EPDCCH is the same as the symbol that detected the initial signal.

The end symbol of the first EPDCCH is the last symbol in a subframe. The end symbol of the second EPDCCH is set based on the parameters of the upper layer.

The PDSCH start and / or end symbols scheduled by the second EPDCCH are determined based on the start and / or end symbols of the second EPDCCH.

The PDSCH start and / or end symbols scheduled by the second EPDCCH are determined based on the DCI in the second EPDCCH.

In the terminal device of the present embodiment, the first serving cell has a first EPDCCH set for monitoring the first EPDCCH, and the second serving cell has a second EPDCCH set for monitoring the second EPDCCH. It includes an upper layer processing unit to be set and a receiving unit that monitors the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

The base station apparatus of the present embodiment has a first EPDCCH set for monitoring the first EPDCCH in the first serving cell and a second EPDCCH set for monitoring the second EPDCCH in the second serving cell. It is provided with an upper layer processing unit for setting the above in the terminal device and a transmission unit for transmitting the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

The maximum number of EREGs that make up each of the ECCEs used to transmit the second EPDCCH is greater than the maximum number of EREGs that make up each of the ECCEs used to transmit the first EPDCCH. large. For example, the number of EREGs that make up each of the ECCEs used to transmit the first EPDCCH comprises 4 or 8. The number of EREGs constituting each of the ECCEs used for the transmission of the second EPDCCH includes a number different from the number of EREGs constituting each of the ECCEs used for the transmission of the first EPDCCH. The number of EREGs that make up each of the ECCEs used to transmit the second EPDCCH comprises 4, 8 or 16.

The resource element to which the demodulation reference signal associated with the second EPDCCH is mapped depends on the start symbol and / or end symbol of the second EPDCCH.

The maximum number of physical resource block pairs used for the second EPDCCH set is greater than the maximum number of physical resource block pairs used for the first EPDCCH set. For example, the number of physical resource block pairs used for the first EPDCCH set includes 2, 4 or 8. The number of physical resource block pairs used for the second EPDCCH set includes a number different from the number of physical resource block pairs used for the first EPDCCH set. Includes 2, 4, 8 or 16.

Moreover, although each of the above-described embodiments has been described using the terms primary cell and PS cell, it is not always necessary to use these terms. For example, the primary cell in each of the above embodiments can be called a master cell, and the PS cell in each of the above embodiments can be called a primary cell.

The program that operates in the base station device 2 and the terminal device 1 according to the present invention is a program that controls a CPU (Central Processing Unit) or the like (a program that functions a computer) so as to realize the functions of the above-described embodiment according to the present invention. ) May be. Then, the information handled by these devices is temporarily stored in a RAM (Random Access Memory) at the time of processing, and then stored in various ROMs such as a Flash ROM (Read Only Memory) or an HDD (Hard Disk Drive). The CPU reads, corrects, and writes as necessary.

The terminal device 1, the base station device 2-1 or a part of the base station device 2-2 in the above-described embodiment may be realized by a computer. In that case, the program for realizing this control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed.

The "computer system" referred to here is a computer system built into the terminal device 1, the base station device 2-1 or the base station device 2-2, and includes hardware such as an OS and peripheral devices. It shall be a computer. The "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system.

Furthermore, a "computer-readable recording medium" is a medium that dynamically holds a program for a short period of time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In that case, a program may be held for a certain period of time, such as a volatile memory inside a computer system serving as a server or a client. Further, the above-mentioned program may be a program for realizing a part of the above-mentioned functions, and may be a program for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Further, the base station device 2-1 or the base station device 2-2 in the above-described embodiment can be realized as an aggregate (device group) composed of a plurality of devices. Each of the devices constituting the device group may include a part or all of each function or each functional block of the base station device 2-1 or the base station device 2-2 according to the above-described embodiment. As the device group, it suffices to have each function or each functional block of the base station device 2-1 or the base station device 2-2. Further, the terminal device 1 according to the above-described embodiment can also communicate with the base station device as an aggregate.

Further, the base station device 2-1 or the base station device 2-2 in the above-described embodiment may be an EUTRAN (Evolved Universal Radio Access Network). Further, the base station device 2-1 or the base station device 2-2 in the above-described embodiment may have a part or all of the functions of the upper node with respect to the eNodeB.

Further, a part or all of the terminal device 1, the base station device 2-1 or the base station device 2-2 in the above-described embodiment may be realized as an LSI that is typically an integrated circuit, or a chipset. It may be realized as. Each functional block of the terminal device 1, the base station device 2-1 or the base station device 2-2 may be individually chipped, or a part or all of them may be integrated into a chip. Further, the method of making an integrated circuit is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, when an integrated circuit technology that replaces an LSI appears due to advances in semiconductor technology, it is also possible to use an integrated circuit based on this technology.

Further, in the above-described embodiment, the cellular mobile station device is described as an example of the terminal device or the communication device, but the present invention is not limited to this, and is a stationary type or non-movable device installed indoors or outdoors. It can also be applied to terminal devices or communication devices such as AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other living equipment.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within a range not departing from the gist of the present invention are also included. Further, the present invention can be variously modified within the scope of the claims, and the technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is done. In addition, the elements described in each of the above embodiments include a configuration in which elements having the same effect are replaced with each other.

(1) In order to achieve the above object, the present invention has taken the following measures. That is, the terminal device according to the uniform state of the present invention is a terminal device that communicates with the base station device, and has a first serving cell, a first EPDCCH set for monitoring a first EPDCCH, and a second serving cell. It includes an upper layer processing unit that sets a second EPDCCH set for monitoring the second EPDCCH, and a receiving unit that monitors the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

(2) Further, the terminal device according to the uniform state of the present invention is the above-mentioned terminal device, and the maximum value among the number of EREGs constituting each of the ECCEs used for the transmission of the second EPDCCH is the first. It is greater than the maximum number of EREGs that make up each of the ECCEs used to transmit EPDCCH.

(3) Further, the terminal device according to the uniform state of the present invention is the above-mentioned terminal device, and the resource element to which the demodulation reference signal associated with the second EPDCCH is mapped depends on the start symbol of the second EPDCCH. It is decided.

(4) Further, the terminal device according to the uniform state of the present invention is the above-mentioned terminal device, and the maximum value among the number of physical resource block pairs used for the second EPDCCH set is the first EPDCCH set. Greater than the maximum number of physical resource block pairs used for.

(5) Further, the base station device according to the uniform state of the present invention is a base station device that communicates with a terminal device, and has a first EPDCCH set for monitoring a first EPDCCH in a first serving cell and a first set. The second serving cell includes an upper layer processing unit that sets a second EPDCCH set for monitoring the second EPDCCH in the terminal device, and a transmission unit that transmits the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

(6) Further, the base station apparatus according to the uniform state of the present invention is the above-mentioned base station apparatus, and the maximum value among the number of EREGs constituting each of the ECCEs used for the transmission of the second EPDCCH is the first. It is larger than the maximum value of the number of EREGs constituting each of the ECCEs used for transmitting one EPDCCH.

(7) Further, the base station apparatus according to the uniform state of the present invention is the above-mentioned base station apparatus, and the resource element to which the demodulation reference signal associated with the second EPDCCH is mapped is used as the start symbol of the second EPDCCH. It depends on.

(8) Further, the base station apparatus according to the uniformity of the present invention is the above-mentioned base station apparatus, and the maximum value among the number of physical resource block pairs used for the second EPDCCH set is the first. Greater than the maximum number of physical resource block pairs used for the EPDCCH set.

(9) Further, the uniform communication method of the present invention is a communication method used for a terminal device that communicates with a base station device, and is a first EPDCCH for monitoring a first EPDCCH in a first serving cell. It has a step of setting a set and a second EPDCCH set for monitoring a second EPDCCH in a second serving cell, and a step of monitoring the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

(10) Further, the uniform communication method of the present invention is a communication method used for a base station device that communicates with a terminal device, and is a first EPDCCH for monitoring a first EPDCCH in a first serving cell. It has a step of setting a set and a second EPDCCH set for monitoring the second EPDCCH in the second serving cell in the terminal device, and a step of transmitting the first EPDCCH and the second EPDCCH. For each physical resource block pair, the EREG used to define the mapping between the first EPDCCH and the second EPDCCH to the resource element is common to the first EPDCCH and the second EPDCCH. The number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH and the number of EREGs constituting each of the ECCEs used for transmitting the first EPDCCH are independently determined.

501 Upper layer 502 Control unit 503 Code word generation unit 504 Downlink subframe generation unit 505 Downlink reference signal generation unit 506 OFDM signal transmission unit 507 Transmission antenna 508 Reception antenna 509 SC-FDMA signal reception unit 510 Uplink subframe processing unit 511 Uplink control information extraction unit 601 Reception antenna 602 OFDM signal reception unit 603 Downlink subframe processing unit 604 Downlink reference signal extraction unit 605 Transport block extraction unit 606, 1006 Control unit 607, 1007 Upper layer 608 Channel state measurement unit 609, 1009 Uplink subframe generation unit 610 Uplink control information generation unit 611, 612, 1011 SC-FDMA signal transmission unit 613, 614, 1013 Transmission antenna

Claims (18)

It is a terminal device (UE)
A receiver set to monitor EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type 3 is provided.
Said terminal device, when detecting a DCI (downlink control information) in the first subframe, the terminal apparatus Kimekomi set of OFDM symbols according to the field included in the DCI of the first subframe,
The OFDM symbol is used for downlink transmission and
The information mapped to the first subframe indicates whether all OFDM symbols are used for downlink transmission in the second subframe following the first subframe.
A terminal device characterized in that a DMRS (demodulation reference signal) associated with the EPDCCH is mapped within the first subframe according to the setting of the OFDM symbol. The terminal device according to claim 1, wherein the first subframe follows one of the lengths of time of the DwPTS (downlink pilot time slot). The terminal device considers that the first X OFDM symbols are used for downlink transmission within the first subframe.
The terminal device according to claim 1, wherein X is determined by a value corresponding to the field. The terminal device according to claim 3, wherein when X is 14, the DMRS is mapped to the 6th and 7th OFDM symbols of both the 1st slot and the 2nd slot. The terminal device according to claim 3, wherein when X is 11, the DMRS is mapped to the third and fourth OFDM symbols of both the first slot and the second slot. The terminal device according to claim 3, wherein when X is 9, the DMRS is mapped to the third, fourth, sixth and seventh OFDM symbols of the first slot. The receiving unit is set to receive PDSCH (physical downlink shared channel), and is set to receive PDSCH (physical downlink shared channel).
The terminal device according to claim 1, wherein the OFDM symbol is used for transmitting a PDSCH. When the first subframe follows the time length of DwPTS of the special subframe settings 3, 4, and 8, the number of EREGs (enhanced resource element groups) per ECCE (enhanced control channel element) is 4.
If the first subframe follows the length of time of the DwPTS of the special subframe settings 1, 2, 6, 7, and 9, the number of EREGs (enhanced resource element group) per ECCE (enhanced control channel element) is The terminal device according to claim 1, wherein the number is 8. A base station device that communicates with a terminal device (UE).
A transmitter set to transmit an EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type 3 is provided.
Said terminal device, when detecting a DCI (downlink control information) in the first subframe, the terminal apparatus Kimekomi set of OFDM symbols according to the field included in the DCI of the first subframe,
The OFDM symbol is used for downlink transmission and
The information mapped to the first subframe indicates whether all OFDM symbols are used for downlink transmission in the second subframe following the first subframe.
A base station apparatus characterized in that a DMRS (demodulation reference signal) associated with the EPDCCH is mapped within the first subframe according to the setting of the OFDM symbol. The base station apparatus according to claim 9, wherein the first subframe follows one of the lengths of time of the DwPTS (downlink pilot time slot). The terminal device considers that the first X OFDM symbols are used for downlink transmission within the first subframe.
The base station apparatus according to claim 9, wherein X is determined by a value corresponding to the field. The base station apparatus according to claim 11, wherein when X is 14, the DMRS is mapped to the 6th and 7th OFDM symbols of both the 1st slot and the 2nd slot. .. The base station apparatus according to claim 11, wherein when X is 11, the DMRS is mapped to the third and fourth OFDM symbols of both the first slot and the second slot. .. The base station apparatus according to claim 11, wherein when X is 9, the DMRS is mapped to the third, fourth, sixth and seventh OFDM symbols of the first slot. The transmitter is set to transmit a PDSCH (physical downlink shared channel).
The base station apparatus according to claim 9, wherein the OFDM symbol is used for transmission of PDSCH. When the first subframe follows the time length of DwPTS of the special subframe settings 3, 4, and 8, the number of EREGs (enhanced resource element groups) per ECCE (enhanced control channel element) is 4.
If the first subframe follows the length of time of the DwPTS of the special subframe settings 1, 2, 6, 7, and 9, the number of EREGs (enhanced resource element group) per ECCE (enhanced control channel element) is The base station apparatus according to claim 9, wherein the number is 8. It is a communication method of the terminal device (UE).
It includes a step of monitoring EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type 3.
Said terminal device, when detecting a DCI (downlink control information) in the first subframe, the terminal apparatus Kimekomi set of OFDM symbols according to the field included in the DCI of the first subframe,
The OFDM symbol is used for downlink transmission and
The information mapped to the first subframe indicates whether all OFDM symbols are used for downlink transmission in the second subframe following the first subframe.
A communication method for a terminal device, wherein the DMRS (demodulation reference signal) associated with the EPDCCH is mapped within the first subframe according to the setting of the OFDM symbol. A communication method for a base station device that communicates with a terminal device (UE).
It includes a step of transmitting an EPDCCH (enhanced physical downlink control channel) on a serving cell using a third frame structure type 3.
Said terminal device, when detecting a DCI (downlink control information) in the first subframe, the terminal apparatus Kimekomi set of OFDM symbols according to the field included in the DCI of the first subframe,
The OFDM symbol is used for downlink transmission and
The information mapped to the first subframe indicates whether all OFDM symbols are used for downlink transmission in the second subframe following the first subframe.
A communication method of a base station apparatus, characterized in that a DMRS (demodulation reference signal) associated with the EPDCCH is mapped within the first subframe according to the setting of the OFDM symbol.

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